PDBsum entry 5a8t

Viral protein

PDB id: 5a8t

Contents

Protein chain

203 a.a.

Waters ×92

PDB id:

5a8t

Name:

Viral protein

Title:

Crystal structure of antheraea mylitta cpv4 polyhedra type 2

Structure:

Polyhedrin. Chain: a. Engineered: yes

Source:

Antheraea mylitta cypovirus 4. Organism_taxid: 180167. Expressed in: spodoptera frugiperda. Expression_system_taxid: 7108. Expression_system_cell_line: sf9.

Resolution:

2.00Å R-factor: 0.178 R-free: 0.239

Authors:

X.Ji,D.Axford,R.Owen,G.Evans,H.M.Ginn,G.Sutton,D.I.Stuart

Key ref:

X.Ji et al. (2015). Polyhedra structures and the evolution of the insect viruses. J Struct Biol, 192, 88-99. PubMed id: 26291392 DOI: 10.1016/j.jsb.2015.08.009

Date:

17-Jul-15 Release date: 02-Sep-15

Protein chain

Q67G25  (Q67G25_9REOV) -  Polyhedrin from Antheraea mylitta cypovirus 4

Seq: 254 a.a.

Struc: 203 a.a.

DOI no: 10.1016/j.jsb.2015.08.009

J Struct Biol 192:88-99 (2015)

PubMed id: 26291392

Polyhedra structures and the evolution of the insect viruses.

X.Ji, D.Axford, R.Owen, G.Evans, H.M.Ginn, G.Sutton, D.I.Stuart.

ABSTRACT

Polyhedra represent an ancient system used by a number of insect viruses to protect virions during long periods of environmental exposure. We present high resolution crystal structures of polyhedra for seven previously uncharacterised types of cypoviruses, four using ab initio selenomethionine phasing (two of these required over 100 selenomethionine crystals each). Approximately 80% of residues are structurally equivalent between all polyhedrins (pairwise rmsd ⩽1.5Å), whilst pairwise sequence identities, based on structural alignment, are as little as 12%. These structures illustrate the effect of 400million years of evolution on a system where the crystal lattice is the functionally conserved feature in the face of massive sequence variability. The conservation of crystal contacts is maintained across most of the molecular surface, except for a dispensable virus recognition domain. By spreading the contacts over so much of the protein surface the lattice remains robust in the face of many individual changes. Overall these unusual structural constraints seem to have skewed the molecule's evolution so that surface residues are almost as conserved as the internal residues.