UMR7257 : CNRS - AIX MARSEILLE UNIV

Home page > en > Research Teams > Teams > Molecular Transport and Signalling > Proteins from crenarchaeal viruses

Proteins from crenarchaeal viruses

Tuesday 28 February 2012, by Miguel ORTIZ-LOMBARDIA

Available translations [English] [français]

Archaeal viruses are known since the early 1970s. However, only recently they have drawn strong interest. Archaeal viruses are particularly interesting from an evolutionary point of view, because their hosts have characteristics that make them resemble both bacteria and eukaryotes. Cells from archaea are closely similar to those from bacteria; therefore, one would expect that archaeal viruses would be similar to bacteriophages. This is actually the case for most viruses infecting euryarchaeota but not for those of the crenarchaeota. In staggering contrast to their evolutionary interest, the biology of crenarchaeal viruses remains largely unknown. This situation mirrors the fact that between 50% and 90% of the open reading frames (ORFs) predicted in the genomes of these viruses have no associated functional annotation.


collaborations:
- present: Prof. Roger Garret, Danish Archaea Centre, Copenhague, Danemark
- past: Dr. David Prangishvili, Institut Pasteur, Paris, France; Herman van Tilbeurgh, Université d’Orsay, Orsay, France.


PNG - 272.6 kb
AFV1 capsid proteins

The VIRAR project, funded by the ANR (Agence Nationale de la Recherche), allowed us to contribute to the study of the structural biology of these viruses, in collaboration with D. Prangishvili (Institut Pasteur, Paris) and Herman van Tilbeurgh (Université d’Orsay). As a result, we have solved the crystal structures of six proteins from crenarchaeal viruses including three structural proteins, one nuclease and two proteins of unknown function. Based on the crystal structure of the two major structural proteins from the capside of the AFV1 lipothrixvirus (PMID:19934032) [1], we have proposed a model accounting for the architecture of the virion.

PNG - 94.1 kb
Structure of ATV-131

Recently, we have focused our interest on the "Acidianus two-tailed virus" (ATV ATV Acidianus two-tailed Virus ), first discovered in 2003 in Pozzuoli, Italy. This virus was isolated from a hot spring at 85 ºC and a pH of 1.5, where its host, the crenarchaea Acidianus convivator thrives. Exceptionally for a virus, ATV ATV Acidianus two-tailed Virus undergoes an extracellular metamorphosis: between one hour and a few days after lysis and release from the host, two tails develop irreversibly at each end of the lemon-shaped virion. This process seems to only depend on temperature, which has to be close to that of the host habitat. We have solved the structure of two proteins from this virus: a structural protein that also binds DNA DNA Desoxyribonucleic Acid and a protein possibly involved in tail development.

Footnotes


[1] Goulet A, Blangy S, Redder P, Prangishvili D, Felisberto-Rodrigues C, Forterre P, Campanacci V, Cambillau C (2009) Proc Natl Acad Sci U S A 106 21155-60

Previous : Baseplates from phages infecting Gram+ bacteries and their fonction in infection
Next : Transcription control by the Hox proteins

© AFMB UMR7257