PDBsum entry 2m4h

Viral protein

PDB id: 2m4h

Contents

Protein chain

67 a.a.

PDB id:

2m4h

Name:

Viral protein

Title:

Solution structure of the core domain (10-76) of the feline calicivirus vpg protein

Structure:

Feline calicivirus vpg protein. Chain: a. Fragment: core domain. Engineered: yes

Source:

Feline calicivirus. Fcv. Organism_taxid: 11981. Strain: f9. Gene: orf1, vpg. Expressed in: escherichia coli. Expression_system_taxid: 469008.

NMR struc:

20 models

Authors:

R.N.Kwok,E.N.Leen,J.R.Birtley,S.N.Prater,P.J.Simpson,S.Curry, S.Matthews,J.Marchant

Key ref:

E.N.Leen et al. (2013). Structures of the compact helical core domains of feline calicivirus and murine norovirus VPg proteins. J Virol, 87, 5318-5330. PubMed id: 23487472 DOI: 10.1128/JVI.03151-12

Date:

05-Feb-13 Release date: 27-Mar-13

Protein chain

P27409  (POLG_FCVF9) -  Genome polyprotein from Feline calicivirus (strain F9)

Seq: 1763 a.a.

Struc: 67 a.a.

Enzyme reactions

• Enzyme class 2: E.C.2.7.7.48 - RNA-directed Rna polymerase.
• Reaction: RNA(n) + a ribonucleoside 5'-triphosphate = RNA(n+1) + diphosphate
• Enzyme class 3: E.C.3.4.22.66 - calicivirin.
• Enzyme class 4: E.C.3.6.1.15 - nucleoside-triphosphate phosphatase.
• Reaction: a ribonucleoside 5'-triphosphate + H2O = a ribonucleoside 5'-diphosphate + phosphate + H⁺

Note, where more than one E.C. class is given (as above), each may correspond to a different protein domain or, in the case of polyprotein precursors, to a different mature protein.

Molecule diagrams generated from .mol files obtained from the KEGG ftp site

reference

DOI no: 10.1128/JVI.03151-12

J Virol 87:5318-5330 (2013)

PubMed id: 23487472

Structures of the compact helical core domains of feline calicivirus and murine norovirus VPg proteins.

E.N.Leen, K.Y.Kwok, J.R.Birtley, P.J.Simpson, C.V.Subba-Reddy, Y.Chaudhry, S.V.Sosnovtsev, K.Y.Green, S.N.Prater, M.Tong, J.C.Young, L.M.Chung, J.Marchant, L.O.Roberts, C.C.Kao, S.Matthews, I.G.Goodfellow, S.Curry.

ABSTRACT

We report the solution structures of the VPg proteins from feline calicivirus (FCV) and murine norovirus (MNV), which have been determined by nuclear magnetic resonance spectroscopy. In both cases, the core of the protein adopts a compact helical structure flanked by flexible N and C termini. Remarkably, while the core of FCV VPg contains a well-defined three-helix bundle, the MNV VPg core has just the first two of these secondary structure elements. In both cases, the VPg cores are stabilized by networks of hydrophobic and salt bridge interactions. The Tyr residue in VPg that is nucleotidylated by the viral NS7 polymerase (Y24 in FCV, Y26 in MNV) occurs in a conserved position within the first helix of the core. Intriguingly, given its structure, VPg would appear to be unable to bind to the viral polymerase so as to place this Tyr in the active site without a major conformation change to VPg or the polymerase. However, mutations that destabilized the VPg core either had no effect on or reduced both the ability of the protein to be nucleotidylated and virus infectivity and did not reveal a clear structure-activity relationship. The precise role of the calicivirus VPg core in virus replication remains to be determined, but knowledge of its structure will facilitate future investigations.