PDBsum entry 1z1u

Virus/viral protein

PDB id: 1z1u

Contents

Protein chains

(+ 0 more) 391 a.a.

Theoretical model

PDB id:

1z1u

Name:

Virus/viral protein

Title:

Model of bacteriophage t4 hexameric capsomers. The model is based on the crystal structure of capsid vertex protein gp24

Structure:

Major capsid protein (g23). Chain: a, b, c, d, e, f

Source:

Bacteriophage t4

Authors:

A.Fokine,P.G.Leiman,M.M.Shneider,B.Ahvazi,K.M.Boeshans, A.C.Steven,L.W.Black,V.V.Mesyanzhinov,M.G.Rossmann

Key ref:

A.Fokine et al. (2005). Structural and functional similarities between the capsid proteins of bacteriophages T4 and HK97 point to a common ancestry. Proc Natl Acad Sci U S A, 102, 7163-7168. PubMed id: 15878991 DOI: 10.1073/pnas.0502164102

Date:

06-Mar-05 Release date: 26-Apr-05

Protein chains

No UniProt id for this chain

Struc: 391 a.a.

DOI no: 10.1073/pnas.0502164102

Proc Natl Acad Sci U S A 102:7163-7168 (2005)

PubMed id: 15878991

Structural and functional similarities between the capsid proteins of bacteriophages T4 and HK97 point to a common ancestry.

A.Fokine, P.G.Leiman, M.M.Shneider, B.Ahvazi, K.M.Boeshans, A.C.Steven, L.W.Black, V.V.Mesyanzhinov, M.G.Rossmann.

ABSTRACT

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.

Selected figure(s)

Figure 1.
Fig. 1. A cryo-EM reconstruction at 22.5-Å resolution of the T4 head capsid is shown. The gene products 23, 24, hoc, and soc are colored blue, magenta, yellow, and pink, respectively. The reconstruction used 5-fold averaging about the long axis of the head. The features of the tail (green) appear blurred because the tail has six-fold symmetry. [Adapted from Fokine et al. (2).

Figure 3.
Fig. 3. Stereo diagram shows the superposition of the C backbones of T4 gp24 (red) and the HK97 capsid protein (blue).

Figures were selected by an automated process.