Structural Conservation Research Articles

IN SILICO ANALYSIS OF IDENTIFIED MOST FREQUENT MUTATIONS IN EXON 10, CODON 618 OF THE HUMAN RET GENE

Background: The Rearranged during Transfection (RET) gene mutations are known to be responsible for Hirschsprung disease (HSCR), as well as the multiple endocrine neoplasia (MEN) types 2A, 2B and familial medullary thyroid carcinoma (FMTC). Aim: In this study we analyse mutations of codon 618 (Cys618Phe, Cys618Arg, Cys618Ser, Cys618Tyr) in exon 10, in terms of their structural similarities, stability, conservation and interaction with their close interactor GFRA3 protein. Material and Methods: In the present study, multiple bioinformatics software was used, including HGMD and UniProt for the data collection. The structural prediction of different mutations at codon 618 was performed by using PSIPRED for secondary structure prediction and I-TASSER for 3D structure modelling. The mutated proteins stability was determined, using I- Mutant and MuPro, while the evolutionary amino acids conservation was assessed with the ConSurf tool. The wildtype RET and mutant proteins were independently docked with their nearby interactor protein GFRA3.Findings: The analysis indicates that among the examined mutations, the Cys618Phe displayed the greatest structural and functional similarity to the wildtype RET protein. The interaction analysis suggested that the Cys618Phe demonstrated stronger binding with GFRA3 compared to other mutations. Conclusion: This study highlights the impact of codon 618 mutations in exon 10 of the RET gene on protein stability, structure, and interactions with GFRA3. We find mutation Cys618Phe comparatively similar to RET wildtype protein while dissimilar mutation Cys618Tyr. These findings could help a molecular geneticist in analyzing mutations at codon 618 for both research and diagnostic purpose.

Evolution of sequence, structural and functional diversity of the ubiquitous DNA/RNA-binding Alba domain

The DNA/RNA-binding Alba domain is prevalent across all kingdoms of life. First discovered in archaea, this protein domain has evolved from RNA- to DNA-binding, with a concomitant expansion in the range of cellular processes that it regulates. Despite its widespread presence, the full extent of its sequence, structural, and functional diversity remains unexplored. In this study, we employed iterative searches in PSI-BLAST to identify 15,161 unique Alba domain-containing proteins from the NCBI non-redundant protein database. Sequence similarity network (SSN) analysis clustered them into 13 distinct subgroups, including the archaeal Alba and eukaryotic Rpp20/Pop7 and Rpp25/Pop6 groups, as well as novel fungal and Plasmodium-specific Albas. Sequence and structural conservation analysis of the subgroups indicated high preservation of the dimer interface, with Alba domains from unicellular eukaryotes notably exhibiting structural deviations towards their C-terminal end. Finally, phylogenetic analysis, while supporting SSN clustering, revealed the evolutionary branchpoint at which the eukaryotic Rpp20- and Rpp25-like clades emerged from archaeal Albas, and the subsequent taxonomic lineage-based divergence within each clade. Taken together, this comprehensive analysis enhances our understanding of the evolutionary history of Alba domain-containing proteins across diverse organisms.

Rendering Proteins Fluorescent Inconspicuously: Genetically Encoded 4‐Cyanotryptophan Conserves Their Structure and Enables the Detection of Ligand Binding Sites

Cyanotryptophans (CN‐Trp) are privileged multimodal reporters on protein structure. They are similar in size to the canonical amino acid tryptophan and some of them exhibit bright fluorescence which responds sensitively to changes in the environment. We selected aminoacyl‐tRNA synthetases specific for 4‐, 5‐, 6‐, and 7‐CN‐Trp for high‐yield in vivo production of proteins with a single, site‐specifically introduced nitrile label. The absorption maximum of 4‐CN‐Trp is distinct from Trp, allowing the selective excitation of its intense fluorescence. 4‐CN‐Trp fluoresces in the visible range with an intensity rivalling that of 7‐hydroxy‐coumarin. Crystal structures of maltose binding protein demonstrate near‐complete structural conservation when a native buried Trp residue is replaced by 4‐CN‐Trp. Besides presenting an inconspicuous tag for live cell microscopy, the high fluorescence of 4‐CN‐Trp enables measurements of subnanomolar ligand binding affinities in isotropic solution, as demonstrated by the complex between rapamycin and the peptidyl–prolyl isomerase FKBP12 furnished with a 4‐CN‐Trp residue in the substrate binding pocket. Furthermore, 4‐CN‐Trp residues positioned at different locations of a protein containing multiple tryptophan residues permits using fluorescence quenching experiments to detect the proximity of individual Trp residues to the binding site of aromatic ligands.

50 Years of Antibody Numbering Schemes: A Statistical and Structural Evaluation Reveals Key Differences and Limitations

Background: The complementarity-determining region (CDR) of antibodies represents the most diverse region both in terms of sequence and structural characteristics, playing the most critical role in antibody recognition and binding for immune responses. Over the past decades, several numbering schemes have been introduced to define CDRs based on sequence. However, the existence of diverse numbering schemes has led to potential confusion, and a comprehensive evaluation of these schemes is lacking. Methods: We employ statistical analyses to quantify the diversity of CDRs compared to the framework regions. Results: Comparative analyses across different numbering schemes demonstrate notable variations in CDR definitions. The Kabat and AbM numbering schemes tend to incorporate more conserved residues into their CDR definitions, whereas CDRs defined by the Chothia and IMGT numbering schemes display greater diversity, sometimes missing certain loop residues. Notably, we identify a critical residue, L29, within the kappa light chain CDR1, which appears to act as a pivotal structural point within the loop. In contrast, most numbering schemes designate the topological equivalent point in the lambda light chain as L30, suggesting the need for further refinement in the current numbering schemes. Conclusions: These findings shed light on regional sequence and structural conservation within antibody sequence databases while also highlighting discrepancies stemming from different numbering schemes. These insights yield valuable guidelines for the precise delineation of antibody CDRs and the strategic design of antibody repertoires, with practical implications in developing innovative antibody-based therapeutics and diagnostics.

Rendering Proteins Fluorescent Inconspicuously: Genetically Encoded 4-Cyanotryptophan Conserves Their Structure and Enables the Detection of Ligand Binding Sites.

Cyanotryptophans (CN-Trp) are privileged multimodal reporters on protein structure. They are similar in size to the canonical amino acid tryptophan and some of them exhibit bright fluorescence which responds sensitively to changes in the environment. We selected aminoacyl-tRNA synthetases specific for 4-, 5-, 6-, and 7-CN-Trp for high-yield in vivo production of proteins with a single, site-specifically introduced nitrile label. The absorption maximum of 4-CN-Trp is distinct from Trp, allowing the selective excitation of its intense fluorescence. 4-CN-Trp fluoresces in the visible range with an intensity rivalling that of 7-hydroxy-coumarin. Crystal structures of maltose binding protein demonstrate near-complete structural conservation when a native buried Trp residue is replaced by 4-CN-Trp. Besides presenting an inconspicuous tag for live cell microscopy, the high fluorescence of 4-CN-Trp enables measurements of subnanomolar ligand binding affinities in isotropic solution, as demonstrated by the complex between rapamycin and the peptidyl-prolyl isomerase FKBP12 furnished with a 4-CN-Trp residue in the substrate binding pocket. Furthermore, 4-CN-Trp residues positioned at different locations of a protein containing multiple tryptophan residues permits using fluorescence quenching experiments to detect the proximity of individual Trp residues to the binding site of aromatic ligands.

Comparative Analysis of Mitogenomes in Leafhopper Tribe Deltocephalini (Hemiptera: Cicadellidae: Deltocephalinae): Structural Conservatism and Phylogeny

ABSTRACTPrevious studies on the gene order and composition of leafhopper mitochondrial genomes have revealed a high level of conservation in overall genome structure. Some members of Deltocephalinae, the largest subfamily, exhibit tRNA gene rearrangements; however, few mitogenomes have been sequenced in this group and the degree of structural variation within tribes remains unclear. In this study, we sequenced the complete mitogenomes of 14 species belonging to four genera of tribe Deltocephalini from China and compared them with the two previously reported mitogenomes for this tribe. The studied mitogenomes showed a high degree of similarity to most other leafhopper mitogenomes in overall structure, mostly varying in the total length (14,961–15,416 bp) and number of non‐coding A + T‐rich regions. Gene size, order, arrangement, base composition, codon usage, and secondary structure of tRNAs in the newly sequenced mitogenomes were highly conserved in Deltocephalini, and variations in start/stop codon usage and tRNA secondary structure mostly matched those of other leafhoppers. Phylogenetic analysis of different combinations of protein‐coding and ribosomal genes using maximum likelihood and Bayesian inference under different models using either amino acid or nucleotide sequences were generally consistent and agreed with the previous nuclear and partial mitochondrial gene sequence data, indicating that complete mitochondrial genomes are phylogenetically informative at different levels of divergence within Deltocephalini and among different leafhoppers species. In addition to Deltocephalini, Deltocephalinae included members of Athysanini and Opsiini formed monophyletic groups. Maximum likelihood and Bayesian inference analyses consistently grouped Graminella nigrinota with Paralimnini, rendering Deltocephalini polyphyletic. The topology consistently divided Deltocephalini into two major branches, with Alobaldia tobae and Polyamia penistenuis forming a well‐supported sister group to the remaining species of the tribe.

The Structural Permissiveness of Triosephosphate Isomerase (TpiA) of Escherichia coli.

Triosephosphate isomerase (TpiA) is widely regarded as an example of an optimally evolved enzyme due to its essential role in biological systems, its structural conservation, and its near-perfect kinetic parameters. In this study, we investigated the structural robustness of the archetypal TpiA variant from Escherichia coli using an in vitro 5-amino acid linker scanning method. The resulting library was introduced into a tpiA mutant strain for functional complementation. From this library, 16 TpiA variants that were phenotypically indistinguishable from the wild-type enzyme were selected for further analysis. Although all variants retained enzymatic activities within the wild-type range, several insertions were found in highly structured protein domains where the linker was expected to cause significant structural perturbations. Despite these potentially disruptive additions, the enzymes maintained their activity even when expressed in a dnaK mutant, suggesting that chaperones did not compensate for structural abnormalities in vivo. Additionally, when these mutant TpiA variants were produced using an in vitro transcription/translation system, they exhibited enzymatic activity comparable to, and in some cases exceeding, that of the non-mutated enzyme. AlphaFold2 exposed that insertions reconstructed the local architecture of the nearby amino acid sequences. The evolutionary implications of this remarkable structural resilience are discussed.

Molecular characteristics and expression pattern of the FAR1 gene during spike sprouting in quinoa

FAR-RED IMPAIRED RESPONSE 1 (FAR1) is a class of transposase-derived transcription factors that play a very important role in the initiation of the photosensitive pigment A (phyA) signaling pathway. Despite their importance, the understanding of the function of FAR1 genes in quinoa is still limited, especially regarding how they affect the spike sprouting response. Quinoa has gained global attention in recent years for its health benefits and potential for sustainable agriculture. In our study, the CqFAR1 gene set in quinoa was characterized using HMMER (PF03101) and BLAST analyses, and 87 genes were identified. The 87 CqFAR1 genes were systematically classified into five groups that showed a high degree of conservation in gene structure and motif composition. Tissue expression profiles of the CqFAR1 gene indicated that the CqFAR1 gene plays a key role throughout the growth and development of quinoa, especially at mid (leaf) and end (spike) stages. By RT-qPCR analysis, we observed significant differences in the expression of the CqFAR1 gene at different developmental stages. Notably, the CqFAR1 gene showed significant expression enhancement at the early stage of quinoa spike sprouting. The results are useful for understanding the role of the CqFAR1 gene in quinoa growth and development and provide theoretical support for quinoa breeding.

The chloroplast genome of Cephalanthera nanchuanica (Orchidaceae): comparative and phylogenetic analysis with other Neottieae species

BackgroundCephalanthera nanchuanica is a terrestrial orchid species and has been red listed as a second-grade protected plant due to its limited distributions in China. Initially classified within a monotypic genus Tangtsinia, this species was later reassigned to Cephalanthera based on morphological and molecular data. However, previous phylogenetic analyses of Cephalanthera using several segment sequences exhibited a low discriminatory power in delineating its relationships.ResultsIn this study, we characterized and comparatively analyzed the complete chloroplast (cp) genome of C. nanchuanica with those of six previously reported Cephalanthera species. Our findings revealed that the cp genome of C. nanchuanica had the typical quadripartite structure, with a size of 161,365 bp and a GC content of 37.27%. A total of 113 unique genes were annotated, among which nearly half of protein-encoding genes (RSCU > 1) showed a preference in codon usage. No structural rearrangements were observed among the cp genomes of Cephalanthera species, except for C. humilis, which displayed structural alterations due to gene loss, relocation, and inverted repeat (IR) expansion/contraction. The cp genomes of Cephalanthera species were highly conserved, with only a small number of SSRs detected, most of which preferred A/T bases. Comparative analysis of cp genomes indicated that IR and coding regions were less divergent than single copy and non-coding regions and eight mutational hotspots were identified. Phylogenetic analysis suggested that the tribe Neottieae was a monophyletic group, divided into five clades. Palmorchis was the earliest-diverging lineage, followed by Cephalanthera. Diplandrorchis was deeply nested within Neottia, forming a clade. Aphyllorchis and Limodorum formed another clade, sister to Epipactis. Within the Cephalanthera clade, C. nanchuanica was sister to C. falcata with a strong support.ConclusionsThis study demonstrated that the cp genome characters of C. nanchuanica are highly similar to those of other Cephalanthera species, except for the mycoheterotrophic species C. humilis. Although the cp genomes of Cephalanthera species (excluding C. humilis) exhibited conservation in genome structure and sequence, SSR repeats and mutational hotspots were identified, which could potentially serve as as molecular markers for distinguishing Cephalanthera species. The phylogenetic analysis based on the protein-coding genes provided high-resolution support for the infrageneric classification. Therefore, cp genome data will be instrumental in resolving the phylogeny of the genus Cephalanthera.

R3DMCS: a web server for visualizing structural variation in RNA motifs across experimental 3D structures from the same organism or across species.

The recent progress in RNA structure determination methods has resulted in a surge of newly solved RNA 3D structures. However, there is an absence of a user-friendly browser-based tool that can facilitate the comparison and visualization of RNA motifs across multiple 3D structures. We introduce R3DMCS, a web server that allows users to compare selected RNA nucleotides across all 3D structures of a given molecule from a given species, or across all 3D structures mapped to a single Rfam family. Starting from one instance of the motif, R3DMCS retrieves, aligns, annotates, organizes, and displays 3D coordinates of corresponding sets of nucleotides from other 3D structures. With R3DMCS, one can explore conformational changes of motifs due to 3D structures being solved in different functional states or different experimental conditions. One can also investigate conservation of 3D structure across species, or changes in 3D structure due to changes in sequence. R3DMCS is open-source software and freely available at https://rna.bgsu.edu/correspondence/ and https://github.com/BGSU-RNA/RNA-3D-correspondence . Supplementary data are available at Bioinformatics online.

FgGET3, an ATPase of the GET Pathway, Is Important for the Development and Virulence of Fusarium graminearum.

GET3 is an ATPase protein that plays a pivotal role in the guided entry of the tail-anchored (GET) pathway. The protein facilitates the targeting and inserting of tail-anchored (TA) proteins into the endoplasmic reticulum (ER) by interacting with a receptor protein complex on the ER. The role of GET3 in various biological processes has been established in yeast, plants, and mammals but not in filamentous fungi. Fusarium graminearum is the major causal agent of Fusarium head blight (FHB), posing a threat to the yield and quality of wheat. In this study, we found that FgGET3 exhibits a high degree of sequence and structural conservation with its homologs across a wide range of organisms. Ectopic expression of FgGET3 in yeast restored the growth defects of the Saccharomyces cerevisiae ScGET3 knock-out mutant. Furthermore, FgGET3 was found to dimerize and localize to the cytoplasm, similar to its homologs in other species. Deletion of FgGET3 in F. graminearum results in decreased fungal growth, fragmented vacuoles, altered abiotic stress responses, reduced conidia production, delayed conidial germination, weakened virulence on wheat spikes and reduced DON production. Collectively, these findings underscore the critical role of FgGET3 in regulating diverse cellular and biological functions essential for the growth and virulence of F. graminearum.

Accounting for Salmon Body Size Declines in Fishery Management Can Reduce Conservation Risks

ABSTRACTChanges in population demographic structure can have tangible but unknown effects on management effectiveness. Fishery management of Pacific salmon is often informed by estimates of the number of spawners expected to produce maximum sustainable yield (SMSY), implicitly assuming that reproductive output per spawner does not change over time. However, many salmon populations have experienced long‐term trends in age, sex and length compositions that have resulted in smaller body sizes of mature fish. We present an empirically based simulation approach for evaluating management implications of declining reproductive output resulting from shifting demographics. We simulated populations with or without demographic trends, selective or unselective harvests, and harvest policies based on assessment methods that did or did not account explicitly for demographic trends when estimating SMSY. A management strategy evaluation showed reduced expected harvests and run sizes when populations exhibited negative demographic trends. Reduced abundances and increased conservation risks (higher probability of falling below an abundance threshold) could be partially mitigated by using stock‐recruitment analyses based on total egg mass instead of spawner abundance, or via precautionary management where target escapements were higher than SMSY, especially in fisheries that selectively removed large fish. Explicit accounting of demographic trends in stock‐recruit analyses resulted in up to 25% higher run sizes and up to 20% lower conservation risks compared to traditional methods when trends toward smaller, younger and male‐biased runs were present in the population. Conservation of population demographic structure may be critical for sustaining productive fish populations and their benefits to ecosystems and people.

A clinical approach for no prep direct composite veneers with opaquer/ tint to reshape a smile: a case report

Dental aesthetic has a profound influence on both self-esteem and social interactions. Patients desire changes in their smiles, while dentists aim for the preservation of dental and adjacent structures, as well as durability. In this context, no-prep resin veneers emerge as a potential solution, as they allow for the preservation of the maximum amount of healthy dental structure, pulp integrity, and dental strength. Nevertheless, treating darkened substrates poses a challenge, and conservative options like composite resins have gained recognition as restorative materials due to their aesthetic qualities and ability to preserve healthy dental tissue. A protocol can help dentists, especially by describing the stages of making direct no-prep veneers, achieving better clinical success. This article presents a clinical step-by-step guide approach to fabricating light-cured composite prepless veneers, using opaque and tints to mask dark backgrounds, and preserving the dental substrate in a patient with multiple restorations, changes in color, and shape. Light-cured composite prepless veneers comply with the principles of biomimetics and offer advantages such as conservation of dental structures, versatility, one-session preparation, cost, mechanical properties, and excellent aesthetics, however, skill with this technique is required.

Description of the mitochondrial genomes of Sichuan Tetrastes sewerzowi (Galliformes: Tetraonidae) and phylogenetic relationship.

The Chinese Grouse (Tetrastes sewerzowi), a rare endemic bird in China, belongs to the Galliformes order and Tetraonidae family. Despite extensive research, subspecies classification remains inadequate, especially in Pingwu, Sichuan. This study sequenced the mitochondrial genome of T. sewerzowi in Wanglang Nature Reserve, Sichuan, analyzed its structural features, and reconstructed phylogenetic relationships within Tetraonidae. The results indicate that the high conservation in mitochondrial genome structure and sequence between the T. sewerzowi from Wanglang, Sichuan and Lianhuashan, Gansu indicates that they may belong to the same subspecies. Furthermore, we observed significant differences in the length of the mitochondrial control region between T. sewerzowi and Tetrastes bonasia. Based on the phylogenetic tree constructed using a comprehensive mitochondrial dataset, we propose the reclassification of the Hazel Grouse genus into two independent genera: Tetrastes and Bonasa. This study is the first to sequence the mitochondrial genome of T. sewerzowi from Sichuan and compare it with populations from Gansu, providing important insights into the distribution pattern of T. sewerzowi subspecies and facilitating the formulation of effective conservation strategies.

Conservation of Waterlogged Wooden Structures from the Late Bronze Age at İnönü Cave (Türkiye)

ABSTRACT During the excavations carried out in the İnönü Cave, located within the Western Black Sea region of Türkiye, four separate floor structures made of wood, dating back to the Late Bronze Age (1436-1123 Cal BCE), were unearthed. The way the corners of the structures are connected shows that the structures were built with the çantı or bell technique, a traditional nail-less wooden architectural form of the Black Sea region. Thanks to the wet and stable environmental conditions within the cave, the wooden floors have survived and are well preserved from the Late Bronze Age to the present day. This study presents the details of the conservation practices developed and deployed in order to ensure that the wooden floors are well protected and remain available for study in the short and medium term.

Vibration vulnerability assessment of heritage structures in Lahore: a step towards sustainable conservation

Lahore is among the most important historical cities in Pakistan, and many cultural heritage structures, such as Shalamar Gardens and Lahore Fort, which are recognised as World Heritage Sites by UNESCO, are located there. The rapid increase in transit operations and infrastructure development in Lahore can increase the vulnerability of nearby heritage structures to ground-borne vibrations. In this study, a vibration vulnerability assessment of the heritage structures present in Lahore was performed with the help of the framework provided by the Federal Transit Administration (FTA), USA. A remote survey was carried out to gather valuable information regarding the distance between the heritage structures and potential vibrational sources, as well as the latitude and longitude of the heritage structures, via the web-based mapping tool Google Earth. A vibration vulnerability map of heritage structures was developed on the basis of a vibration vulnerability assessment to make it convenient for policymakers to visualise the present state of heritage structures with respect to vibration vulnerability. The performed vibration vulnerability assessment was validated by experimentally measuring vibrations at the Buddha’s Tomb (Buddha Ka Awa) heritage structure. The study revealed that 17% of the heritage structures present in Lahore are vulnerable to vibrations at present, with potential vibrational sources such as road traffic, metro trains, and rail traffic. The vibration vulnerability assessment revealed that 72% of the vibrationally vulnerable heritage structures in Lahore are most influenced by vibrations from road traffic. The results of this study can aid policymakers in creating intervention packages for vibrationally vulnerable heritage structures in Lahore in relation to their respective needs, which will make it possible to achieve the sustainable conservation of heritage structures.

Comparing two different types of stochastic parametrization in geophysical flow

This paper investigates the effects of stochastic variations in bathymetry on the solutions of the thermal quasi-geostrophic (TQG) equations. These stochastic perturbations generate a variety of different types of ensemble spread in the solution behavior whilst also preserving the deterministic Lie–Poisson structure and Casimir conservation laws. We numerically compare the solution sensitivity to another type of structure-preserving stochastic perturbation where instead of bathymetry, the velocity is stochastically perturbed.

Systematical characterization of Rab7 gene family in Gossypium and potential functions of GhRab7B3-A gene in drought tolerance

BackgroundCotton serves as a primary source of natural fibers crucial for the textile industry. However, environmental elements such as drought have posed challenges to cotton cultivation, resulting in adverse impacts on both production and fiber quality. Improving cotton’s resilience to drought could mitigate yield losses and foster the expansion of cotton farming. Rab7 protein, widely present in organisms, controls the degradation and recycling of cargo, and has a potential role in biotic and abiotic tolerance. However, comprehensive exploration of the Rab7 gene family in Gossypium remains scarce.ResultsHerein, we identified a total of 10, 10, 20, and 20 Rab7 genes through genome-wide analysis in Gossypium arboreum, Gossypium raimondii, Gossypium hirsutum, and Gossypium barbadense, respectively. Collinearity analysis unveiled the pivotal role of whole genome or segmental duplication events in the expansion of GhRab7s. Study of gene architecture, conserved protein motifs, and domains suggested the conservation of structure and function throughout evolution. Exploration of cis-regulatory elements revealed the responsiveness of GhRab7 genes to abiotic stress, corroborated by transcriptome analysis under diverse environmental stresses. Notably, the greatly induced expression of GhRab7B3-A under drought treatment prompted us to investigate its function through virus-induced gene silencing (VIGS) assays. Silencing GhRab7B3-A led to exacerbated dehydration and wilting compared with the control. Additionally, inhibition of stomatal closure, antioxidant enzyme activities and expression patterns of genes responsive to abiotic stress were observed in GhRab7B3-A silenced plants.ConclusionsThis study sheds light on Rab7 members in cotton, identifies a gene linked to drought stress, and paves the way for additional investigation of Rab7 genes associated with drought stress tolerance.

A potently neutralizing and protective human antibody targeting antigenic site V on RSV and hMPV fusion glycoprotein.

Human respiratory syncytial virus (RSV) and human metapneumovirus (hMPV) are frequent drivers of morbidity and mortality in susceptible populations, most often infantile, older adults, and immunocompromised. The primary target of neutralizing antibodies is the fusion (F) glycoprotein on the surface of the RSV and hMPV virion. As a result of the structural conservation between RSV and hMPV F, three antigenic regions are known to induce cross-neutralizing responses: sites III, IV, and V. Leveraging LIBRA-seq, we identify five RSV/hMPV cross-reactive human antibodies. One antibody, 5-1, potently neutralizes all tested viruses from the major subgroups of RSV and hMPV and provides protection against RSV and hMPV in a mouse challenge model. Structural analysis reveals that 5-1 utilizes an uncommon genetic signature to bind an epitope that spans sites Ø, II and V, defining a new mode of antibody cross-reactivity between RSV and hMPV F. These findings highlight the molecular and structural elements influencing RSV and hMPV cross-reactivity as well as the potential of antibody 5-1 for translational development.

Comparative analysis of complete chloroplast genomes of 14 Asteraceae species.

The Asteraceae family, the largest and one of the most diverse families of angiosperms, presents significant challenges in taxonomic classification and systematic research due to its vast species diversity and morphological complexity. A comprehensive understanding of the chloroplast genomes within this family is essential for refining taxonomic classifications and advancing phylogenetic studies. In this study, we sequenced the complete chloroplast genomes of 14 Asteraceae species and conducted a thorough bioinformatic analysis of their characteristics. The chloroplast genomes, ranging from 150,907bp to 152,858bp, exhibit a typical quadripartite structure: a large single-copy (LSC) region (83,044bp to 84,625bp), a small single-copy (SSC) region (18,223bp to 18,673bp), and a pair of inverted repeats (IRs) (24,806bp to 25,201bp). These genomes encode 87 to 89 protein-coding genes (PCGs), 36 to 37 tRNA genes, and 8 rRNA genes, with high conservation in size, structure, gene content, and order. Comparative analysis with other Asteraceae species' chloroplast genomes revealed notable similarities and structural variations, particularly in the IR regions. Nucleotide polymorphism analysis identified four genes-trnY-GUA, trnE-UUC, ycf1, and rrn23-with higher Pi values, suggesting potential hotspots for evolutionary studies. Phylogenetic analysis using maximum likelihood (ML) and Bayesian inference (BI) approaches provided new insights, proposing the reclassification of Himalaiella auriculata and Jacobaea raphanifolia as independent genera, distinct from Saussurea and Senecio. This study presents a comprehensive analysis of the chloroplast genome structures and phylogenetic relationships of 14 Asteraceae species, offering critical data for future molecular identification, evolutionary biology, and population genetics research. The findings hold significant implications for the ongoing refinement of Asteraceae taxonomic classifications and enhance our understanding of the evolutionary dynamics within this complex family.