2j6c
From Proteopedia
|
CRYSTAL STRUCTURE OF AFV3-109, A HIGHLY CONSERVED PROTEIN FROM CRENARCHAEAL VIRUSES
Overview
The extraordinary morphologies of viruses infecting hyperthermophilic, archaea clearly distinguish them from bacterial and eukaryotic viruses., Moreover, their genomes code for proteins that to a large extend have no, related sequences in the extent databases. However, a small pool of genes, is shared by overlapping subsets of these viruses, and the most conserved, gene, exemplified by the ORF109 of the Acidianus Filamentous Virus 3, AFV3, is present on genomes of members of three viral familes, the, Lipothrixviridae, Rudiviridae, and "Bicaudaviridae", as well as of the, unclassified Sulfolobus Turreted Icosahedral Virus, STIV. We present here, the crystal structure of the protein (Mr = 13.1 kD, 109 residues) encoded, by the AFV3 ORF 109 in two different crystal forms at 1.5 and 1.3 A, resolution. The structure of AFV3-109 is a five stranded beta-sheet with, loops on one side and three helices on the other. It forms a dimer, adopting the shape of a cradle that encompasses the best conserved regions, of the sequence. No protein with a related fold could be identified except, for the ortholog from STIV1, whose structure was deposited at the Protein, Data Bank. We could clearly identify a well bound glycerol inside the, cradle, contacting exclusively totally conserved residues. This, interaction was confirmed in solution by fluorescence titration. Although, the function of AFV3-109 cannot be deduced directly from its structure, structural homology with the STIV1 protein, and the size and charge, distribution of the cavity suggested it could interact with nucleic acids., Fluorescence quenching titrations also showed that AFV3-109 interacts with, dsDNA. Genomic sequence analysis revealed bacterial homologs of AFV3-109, as a part of a putative previously unidentified prophage sequences in some, Firmicutes.
About this Structure
2J6C is a Single protein structure of sequence from Acidianus filamentous virus 1 with GOL as ligand. Known structural/functional Site: . Full crystallographic information is available from OCA.
Reference
Crystal structure of AFV3-109, a highly conserved protein from crenarchaeal viruses., Keller J, Leulliot N, Cambillau C, Campanacci V, Porciero S, Prangishvilli D, Forterre P, Cortez D, Quevillon-Cheruel S, van Tilbeurgh H, Virol J. 2007 Jan 22;4:12. PMID:17241456
Page seeded by OCA on Tue Dec 18 19:50:55 2007
