SWISS-PROT Protein Sequence Data Bank Research Articles

On the frequency of protein glycosylation, as deduced from analysis of the SWISS-PROT database

The SWISS-PROT protein sequence data bank contains at present nearly 75 000 entries, almost two thirds of which include the potential N-glycosylation consensus sequence, or sequon, NXS/T (where X can be any amino acid but proline) and thus may be glycoproteins. The number of proteins filed as glycoproteins is however considerably smaller, 7942, of which 749 have been characterized with respect to the total number of their carbohydrate units and sites of attachment of the latter to the protein, as well as the nature of the carbohydrate-peptide linking group. Of these well characterized glycoproteins, about 90% carry either N-linked carbohydrate units alone or both N- and O-linked ones, attached at 1297 N-glycosylation sites (1.9 per glycoprotein molecule) and the rest are O-glycosylated only. Since the total number of sequons in the well characterized glycoproteins is 1968, their rate of occupancy is 2/3. Assuming that the same number of N-linked units and rate of sequon occupancy occur in all sequon containing proteins and that the proportion of solely O-glycosylated proteins (ca. 10%) will also be the same as among the well characterized ones, we conclude that the majority of sequon containing proteins will be found to be glycosylated and that more than half of all proteins are glycoproteins.

Making sense of the human proteome

Now that the task of sequencing the genome is well under way (the first draft of the human genome sequence will be made available in the first few months of next year), the focus of research will switch to the protein level, relating sequences and, where possible, structures to protein function. In June, Amos Bairoch (Swiss Institute of Bioinformatics, Switzerland), the curator of the SwissProt protein sequence database (http://www.expasy.ch/sprot) 1 Bairoch A. Apweiler R. The SWISS-PROT protein sequence data bank and its supplement TrEMBL in 1999. Nucleic Acids Res. 1999; 27: 49-54 Crossref PubMed Scopus (456) Google Scholar , announced a project to ensure that high-quality human protein sequence data are released into the public domain as soon as practicable – the Human Proteomics Initiative (http://www.expasy.ch/sprot/hpi).

The PLAT domain: a new piece in the PKD1 puzzle

The PLAT domain: a new piece in the PKD1 puzzle

Removing redundancy in SWISS-PROT and TrEMBL.

One of the distinguishing criteria of the SWISS-PROT protein sequence data bank is minimal redundancy. The introduction of TrEMBL as a supplementary database ensured the comprehensiveness of SWISS-PROT and TrEMBL but introduced some degree of redundancy. We developed a strategy to identify the redundancy present within and between SWISS-PROT and TrEMBL and its subsequent removal. The tools mentioned in this paper are available on request.

The SWISS-PROT protein sequence data bank and its supplement TrEMBL in 1999.

SWISS-PROT is a curated protein sequence database which strives to provide a high level of annotation (such as the description of the function of a protein, its domain structure, post-translational modifications, variants, etc.), a minimal level of redundancy and high level of integration with other databases. Recent developments of the database include: cross-references to additional databases; a variety of new documentation files and improvements to TrEMBL, a computer annotated supplement to SWISS-PROT. TrEMBL consists of entries in SWISS-PROT-like format derived from the translation of all coding sequences (CDS) in the EMBL nucleotide sequence database, except the CDS already included in SWISS-PROT. The URLs for SWISS-PROT on the WWW are: http://www.expasy.ch/sprot and http://www. ebi.ac.uk/sprot

The SWISS-PROT protein sequence data bank and its supplement TrEMBL in 1998.

SWISS-PROT (http://www.expasy.ch/) is a curated protein sequence database which strives to provide a high level of annotations (such as the description of the function of a protein, its domains structure, post-translational modifications, variants, etc.), a minimal level of redundancy and high level of integration with other databases. Recent developments of the database include: an increase in the number and scope of model organisms; cross-references to two additional databases; a variety of new documentation files and improvements to TrEMBL, a computer annotated supplement to SWISS-PROT. TrEMBL consists of entries in SWISS-PROT-like format derived from the translation of all coding sequences (CDS) in the EMBL nucleotide sequence database, except the CDS already included in SWISS-PROT.

The SWISS-PROT protein sequence data bank and its supplement TrEMBL.

SWISS-PROT is a curated protein sequence database which strives to provide a high level of annotations (such as the description of the function of a protein, structure of its domains, post-translational modifications, variants, etc.), a minimal level of redundancy and high level of integration with other databases. Recent developments of the database include: an increase in the number and scope of model organisms; cross-references to two additional databases; a variety of new documentation files and the creation of TrEMBL, a computer annotated supplement to SWISS-PROT. This supplement consists of entries in SWISS-PROT-like format derived from the translation of all coding sequences (CDS) in the EMBL nucleotide sequence database, except the CDS already included in SWISS-PROT.

Identification of the active-site peptide of 2,3-dihydroxybenzoic acid decarboxylase from Aspergillus oryzae

The non-oxidative decarboxylation of aromatic acids is a poorly understood reaction. The transformation of 2,3-dihydroxybenzoic acid to catechol in the fungal metabolism of indole is a prototype of such a reaction. 2,3-Dihydroxybenzoic acid decarboxylase (EC 4.1.1.46) which catalyzes this reaction was purified to homogeneity from anthranilate induced cultures of Aspergillus oryzae using affinity chromatography. The enzyme did not require cofactors like NAD +, PLP, TPP or metal ions for its activity. There was no spectral evidence for the presence of enzyme bound cofactors. The preparation, which was adjudged homogeneousy by the criteria of SDS-PAGE, sedimentation analysis and N-terminal analysis, was characterized for its physicochemical and kinetic parameters. The enzyme was inactivated by group-specific modifiers like diethyl pyrocarbonate (DEPC) and N-ethylmaleimide (NEM). The kinetics of inactivation by DEPC suggested the presence of a single class of essential histidine residues, the second order rate constant of inactivation for which was 12.5 M −1 min −1. A single class of a cysteine residues was modified by NEM with a second order rate constant of 33 M −1 min −1. Substrate analogues protected the enzyme against inactivation by both DEPC and NEM, suggesting the location of the essential histidine and cysteine to be at the active site of the enzyme. The incorporation of radiolabelled NEM in a differential labelling experiment was 0.73 mol per mol subunit confirming the presence of a single essential cysteine per active-site. Differentially labelled enzyme was enzymatically cleaved and the peptide bearing the label was purified and sequenced. The active-site peptide LLGLAETCK and the N-terminal sequence MLGKIALEEAFALPRFEEKT did not bear any similarity to sequenced. The active-site peptide LLGLAETCK and the Databank, a reflection probably of the unique primary structure of this novel enzyme. The sequences reported in this study will appear in the Swiss-Prot Protein Sequence Databank under the accession number P80402.

The SWISS-PROT protein sequence data bank and its new supplement TREMBL.

SWISS-PROT is a curated protein sequence database which strives to provide a high level of annotation (such as the description of the function of a protein, its domain structure, post-translational modifications, variants, etc), a minimal level of redundancy and a high level of integration with other databases. Recent developments of the database include: an increase in the number and scope of model organisms; cross-references to seven additional databases; a variety of new documentation files; the creation of TREMBL, and unannotated supplement to SWISS-PROT. This supplement consists of entries in SWISS-PROT-like format derived from the translation of all coding sequences (CDS) in the EMBL nucleotide sequence database, except CDS already included in SWISS-PROT.

DR4Dw4/DR53 molecules contain a peptide from the autoantigen calreticulin

Rheumatoid arthritis (RA) occurs more frequently in HLA-DR4+ individuals than in those who do not express this MHC class II molecule. Although the role of this genetic factor in the immunopathology of this autoimmune disease is unclear, the association of RA with HLA-DR4 may indicate that DR4 molecules present autoantigen(s) to T cells. Here we report the analysis of naturally processed peptides, eluted from a mixture of HLA-DR4Dw4 (DRB1*0401) and DR53 (DRB4*0101) molecules isolated from an RA patient-derived EBV-transformed B cell line. Several (size variants of) self-peptides originating from the autologous molecules HLA-A2, HLA-Cw9, HLA-B62, HLA-DR4Dw4 and HLA-DR53, were identified. We also found a sequence that has no homology to any protein in the SwissProt protein sequence databank, and a peptide identical to an internal fragment of the autoantigen calreticulin. The association of the identified peptides with cells expressing HLA-DR4Dw4/DR53 was confirmed by peptide binding analysis. In agreement with previously described peptide binding motifs for DR4Dw4, most peptides contained an aromatic residue (Phe, Tyr, Trp) at relative position i and a small hydroxyl-containing residue (Ser, Thr) at i + 5. Our findings indicate that in RA patient-derived EBV-transformed B cells DR4Dw4/DR53 molecules present a peptide from the autoantigen calreticulin. Interestingly, autoantibodies against calreticulin have been found in various rheumatic diseases, including rheumatoid arthritis. Thus, the analysis of HLA class II-bound peptides can lead to the identification of putative T helper epitopes, which might be involved in the immunopathology of autoimmune diseases.

New families in the classification of glycosyl hydrolases based on amino acid sequence similarities.

301 glycosyl hydrolases and related enzymes corresponding to 39 EC entries of the I.U.B. classification system have been classified into 35 families on the basis of amino-acid-sequence similarities [Henrissat (1991) Biochem. J. 280, 309-316]. Approximately half of the families were found to be monospecific (containing only one EC number), whereas the other half were found to be polyspecific (containing at least two EC numbers). A > 60% increase in sequence data for glycosyl hydrolases (181 additional enzymes or enzyme domains sequences have since become available) allowed us to update the classification not only by the addition of more members to already identified families, but also by the finding of ten new families. On the basis of a comparison of 482 sequences corresponding to 52 EC entries, 45 families, out of which 22 are polyspecific, can now be defined. This classification has been implemented in the SWISS-PROT protein sequence data bank.

A cryptic DNA sequence, isolated from Actinobacillus pleuropneumoniae, confers a hemolytic activity upon Escherichia coli K12 strains.

A hemolytic recombinant clone on Escherichia coli was obtained from a genomic library of Actinobacillus pleuropneumoniae. The clone possessed a recombinant plasmid, pHLY1, carrying an insert DNA of 1 kilobases. A 21 kilodaltons protein, which is assumed to be a fusion protein with a tetracycline resistant protein of pBR322, was encoded by pHLY1. The nucleotide sequence and its deduced amino acid sequence were different from those of the previously reported hemolysin genes of A. pleuropneumoniae. Furthermore, the amino acid sequence did not show a significant homology with other published sequences in the SWISS-PROT Protein Sequence Data Bank.

The SWISS-PROT protein sequence data bank, recent developments.

The SWISS-PROT protein sequence data bank, recent developments.

SRS--an indexing and retrieval tool for flat file data libraries.

SRS (Sequence Retrieval System) is an information indexing and retrieval system designed for libraries with a flat file format such as the EMBL nucleotide sequence databank, the SwissProt protein sequence databank or the Prosite library of protein subsequence consensus patterns. SRS supports the data structure of these libraries by providing special indices for implementing lists of subentities (e.g. feature tables) or hierarchically structured data-fields (e.g. taxonomic classification). A language (ODD) has been designed for the convenient specification of library format and organization, representation of individual data-fields within the system (design of indices) and structuring other data needed during retrieval. This ensures flexibility required for coping with different library formats, which are subject to continuous change. Queries and inspection of retrieved entries can be performed from a user interface with pull-down menus and windows. SRS supports various input and output formats but is particularly well adapted to the GCG programs.

The transcriptional control proteins c-Myb and v-Myb contain a basic region DNA binding motif

A class of transcriptional control proteins, typified by c-Myb, are characterised by a highly conserved N-terminal DNA binding domain, which is composed of either 2 or 3 imperfect repeats of about 52 amino acids. A sequence homology search of the SWISSPROT protein sequence data bank with this region from mouse c-Myb has allowed us to identify an area near the C-terminus of repeat 2 that contains a short sequence motif, known as the basic region, which forms the DNA binding site in both leucine zipper and helix-loop-helix transcription factors. We therefore propose that this region of repeat 2 and the homologous part of repeat 3 will form the Myb DNA binding site.

The SWISS-PROT protein sequence data bank

Journal Article The SWISS-PROT protein sequence data bank Get access Amos Bairoch, Amos Bairoch Department of Medical Biochemistry, University of Geneva1 rue Michel Servet, 1211 Geneva 4, Switzerland Search for other works by this author on: Oxford Academic PubMed Google Scholar Brigitte Boeckmann Brigitte Boeckmann 1European Molecular Biology LaboratoryHeidelberg, FRG Search for other works by this author on: Oxford Academic PubMed Google Scholar Nucleic Acids Research, Volume 19, Issue suppl, 25 April 1991, Pages 2247–2249, https://doi.org/10.1093/nar/19.suppl.2247 Published: 25 April 1991