The Robust Self-Assembling Tubular Nanostructures Formed by gp053 from Phage vB_EcoM_FV3.

Eugenijus Šimoliūnas,Rolandas Meškys,Simona Povilonienė,Lidija Truncaitė,Mindaugas Valius,Algirdas Kaupinis,Karolis Goda,Rasa Rutkienė

doi:10.3390/v11010050

Eugenijus Šimoliūnas, Rolandas Meškys + Show 6 more

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https://doi.org/10.3390/v11010050

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Journal: Viruses	Publication Date: Jan 11, 2019
Citations: 8	License type: CC BY 4.0

Affiliation: Vilnius University

Abstract

The recombinant phage tail sheath protein, gp053, from Escherichia coli infecting myovirus vB_EcoM_FV3 (FV3) was able to self-assemble into long, ordered and extremely stable tubular structures (polysheaths) in the absence of other viral proteins. TEM observations revealed that those protein nanotubes varied in length (~10–1000 nm). Meanwhile, the width of the polysheaths (~28 nm) corresponded to the width of the contracted tail sheath of phage FV3. The formed protein nanotubes could withstand various extreme treatments including heating up to 100 °C and high concentrations of urea. To determine the shortest variant of gp053 capable of forming protein nanotubes, a set of N- or/and C-truncated as well as poly-His-tagged variants of gp053 were constructed. The TEM analysis of these mutants showed that up to 25 and 100 amino acid residues could be removed from the N and C termini, respectively, without disturbing the process of self-assembly. In addition, two to six copies of the gp053 encoding gene were fused into one open reading frame. All the constructed oligomers of gp053 self-assembled in vitro forming structures of different regularity. By using the modification of cysteines with biotin, the polysheaths were tested for exposed thiol groups. Polysheaths formed by the wild-type gp053 or its mutants possess physicochemical properties, which are very attractive for the construction of self-assembling nanostructures with potential applications in different fields of nanosciences.

Highlights

Over the past decades, the construction of various nanostructures, based on self-assembling biomolecules, is of special interest for both an understanding of the fundamental point of view as well as due to the enormous potential for application in industry, medicine and many other areas [1,2,3]
During the process of virion assembly inside the cell, the length of the tail sheath is determined by the length of the tail tape measure protein, which is used as a scaffold for the polymerisation of both tail tube and tail sheath proteins
Results of the enterobacteria phage FV3 [44] had the closest identity (96–99%) to the tail sheath proteins from the eleven Escherichia infecting bacteriophages, which belonged to the genus

Summary

Introduction

The construction of various nanostructures, based on self-assembling biomolecules, is of special interest for both an understanding of the fundamental point of view as well as due to the enormous potential for application in industry, medicine and many other areas [1,2,3]. Filamentous bacteriophage M13 and its relatives are the phages of choice, most often used for the construction of genetically engineered viruses, which have been adapted to build phage-based nanosensors, liquid crystals and films [16,17], micro- and nanofibers [14,18], as well as having use in tissue regeneration and to build other functional materials [19,20,21,22,23], or to fabricate nanorings [24]. The construction of self-assembling structures, made from the genetically engineered recombinant proteins of tailed bacteriophages, including podoviruses P22, phi29 [25,26] and myovirus T4 [4,27,28], have been reported. When the sheath reaches the length of the tube, the tail terminator protein binds to the tail tube terminator protein and the last row of the tail sheath subunits to complete the tail, which becomes available for attachment to the head [31,33]

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