1yue

From Proteopedia

Revision as of 13:27, 20 March 2008

Bacteriophage T4 capsid vertex protein gp24

Overview

Gene product (gp) 24 of bacteriophage T4 forms the pentameric vertices of the capsid. Using x-ray crystallography, we found the principal domain of gp24 to have a polypeptide fold similar to that of the HK97 phage capsid protein plus an additional insertion domain. Fitting gp24 monomers into a cryo-EM density map of the mature T4 capsid suggests that the insertion domain interacts with a neighboring subunit, effecting a stabilization analogous to the covalent crosslinking in the HK97 capsid. Sequence alignment and genetic data show that the folds of gp24 and the hexamer-forming capsid protein, gp23*, are similar. Accordingly, models of gp24* pentamers, gp23* hexamers, and the whole capsid were built, based on a cryo-EM image reconstruction of the capsid. Mutations in gene 23 that affect capsid shape map to the capsomer's periphery, whereas mutations that allow gp23 to substitute for gp24 at the vertices modify the interactions between monomers within capsomers. Structural data show that capsid proteins of most tailed phages, and some eukaryotic viruses, may have evolved from a common ancestor.

About this Structure

1YUE is a Single protein structure of sequence from Bacteriophage t4. Full crystallographic information is available from OCA.

Reference

Structural and functional similarities between the capsid proteins of bacteriophages T4 and HK97 point to a common ancestry., Fokine A, Leiman PG, Shneider MM, Ahvazi B, Boeshans KM, Steven AC, Black LW, Mesyanzhinov VV, Rossmann MG, Proc Natl Acad Sci U S A. 2005 May 17;102(20):7163-8. Epub 2005 May 6. PMID:15878991

Page seeded by OCA on Thu Mar 20 15:27:38 2008