Acidianus filamentous virus 1 coat proteins display a helical fold spanning the filamentous archaeal viruses lineage.
Acidianus filamentous virus 1 (AFV1), a member of the Lipothrixviridae family, infects the hyperthermophilic, acidophilic crenarchaeaon Acidianus hospitalis. The virion, covered with a lipidic outer shell, is 9,100-A long and contains a 20.8-kb linear dsDNA genome. We have identified the two major coat proteins of the virion (MCPs; 132 and 140 amino acids). They bind DNA and form filaments when incubated with linear dsDNA. A C-terminal domain is identified in their crystal structure with a four-helix-bundle fold. In the topological model of the virion filament core, the genomic dsDNA superhelix wraps around the AFV1-132 basic protein, and the AFV1-140 basic N terminus binds genomic DNA, while its lipophilic C-terminal domain is imbedded in the lipidic outer shell. The four-helix bundle fold of the MCPs from AFV1 is identical to that of the coat protein (CP) of Sulfolobus islandicus rod-shaped virus (SIRV), a member of the Rudiviridae family. Despite low sequence identity between these proteins, their high degree of structural similarity suggests that they could have derived from a common ancestor and could thus define an yet undescribed viral lineage.
Goulet
Adeline
A
Architecture et Fonction des Macromolécules Biologiques, Centre national de la Recherche Scientifique and Universités Aix-Marseille I & II, Architecture et Fonction des Macromolécules Biologiques, Unité Mixte de Recherche 6098, Case 932, 163 avenue de Luminy, 13288 Marseille Cedex 9, France.
Blangy
Stéphanie
S
Redder
Peter
P
Prangishvili
David
D
Felisberto-Rodrigues
Catarina
C
Forterre
Patrick
P
Campanacci
Valérie
V
Cambillau
Christian
C
D041541:Acidianus / Q000821:virology; D036022:Capsid Proteins / Q000737:chemistry*; D018360:Crystallography, X-Ray; D004268:DNA-Binding Proteins / Q000737:chemistry; D016679:Genome, Viral; D023643:Lipothrixviridae / Q000737:chemistry* / Q000235:genetics; D008969:Molecular Sequence Data; D010802:Phylogeny; D017510:Protein Folding; D017433:Protein Structure, Secondary; D040681:Structural Homology, Protein; D016944:Sulfolobus / Q000737:chemistry
D036022:Capsid Proteins; D004268:DNA-Binding Proteins