PDBsum entry 5tjt

Viral protein

PDB id: 5tjt

Contents

Protein chains

(+ 0 more) 292 a.a.

PDB id:

5tjt

Name:

Viral protein

Title:

T5 bacteriophage major capsid protein - one pb8 hexon

Structure:

Major capsid protein. Chain: a, b, c, d, e, f. Fragment: unp residues 160-458. Synonym: capsid protein pb8,major head protein

Source:

Escherichia phage t5. Organism_taxid: 10726

Authors:

J.Conway,A.Huet

Key ref:

E.Vernhes et al. (2017). High affinity anchoring of the decoration protein pb10 onto the bacteriophage T5 capsid. Sci Rep, 7, 41662. PubMed id: 28165000

Date:

05-Oct-16 Release date: 22-Feb-17

Protein chains

Q6QGD8  (CAPSD_BPT5) -  Major capsid protein from Escherichia phage T5

Seq: 458 a.a.

Struc: 292 a.a.

Sci Rep 7:41662 (2017)

PubMed id: 28165000

High affinity anchoring of the decoration protein pb10 onto the bacteriophage T5 capsid.

E.Vernhes, M.Renouard, B.Gilquin, P.Cuniasse, D.Durand, P.England, S.Hoos, A.Huet, J.F.Conway, A.Glukhov, V.Ksenzenko, E.Jacquet, N.Nhiri, S.Zinn-Justin, P.Boulanger.

ABSTRACT

Bacteriophage capsids constitute icosahedral shells of exceptional stability that protect the viral genome. Many capsids display on their surface decoration proteins whose structure and function remain largely unknown. The decoration protein pb10 of phage T5 binds at the centre of the 120 hexamers formed by the major capsid protein. Here we determined the 3D structure of pb10 and investigated its capsid-binding properties using NMR, SAXS, cryoEM and SPR. Pb10 consists of an α-helical capsid-binding domain and an Ig-like domain exposed to the solvent. It binds to the T5 capsid with a remarkably high affinity and its binding kinetics is characterized by a very slow dissociation rate. We propose that the conformational exchange events observed in the capsid-binding domain enable rearrangements upon binding that contribute to the quasi-irreversibility of the pb10-capsid interaction. Moreover we show that pb10 binding is a highly cooperative process, which favours immediate rebinding of newly dissociated pb10 to the 120 hexamers of the capsid protein. In extreme conditions, pb10 protects the phage from releasing its genome. We conclude that pb10 may function to reinforce the capsid thus favouring phage survival in harsh environments.