PDBsum entry 5e6f

Viral protein

PDB id: 5e6f

Contents

Protein chains

130 a.a.

Ligands

TAR

Metals

_MG ×2

Waters ×35

PDB id:

5e6f

Name:

Viral protein

Title:

Canarypox virus resolvase

Structure:

Cnpv261 holliday junction resolvase protein. Chain: a, b. Engineered: yes

Source:

Canarypox virus. Cnpv. Organism_taxid: 44088. Gene: cnpv261. Expressed in: escherichia coli. Expression_system_taxid: 469008.

Resolution:

2.60Å R-factor: 0.223 R-free: 0.264

Authors:

H.Li,Y.Hwang,K.Perry,F.D.Bushman,G.D.Van Duyne

Key ref:

H.Li et al. (2016). Structure and Metal Binding Properties of a Poxvirus Resolvase. J Biol Chem, 291, 11094-11104. PubMed id: 27013661 DOI: 10.1074/jbc.M115.709139

Date:

09-Oct-15 Release date: 30-Mar-16

Protein chains

Q6VZ86  (Q6VZ86_CNPV) -  CNPV261 Holliday junction resolvase protein from Canarypox virus

Seq: 152 a.a.

Struc: 130 a.a.

DOI no: 10.1074/jbc.M115.709139

J Biol Chem 291:11094-11104 (2016)

PubMed id: 27013661

Structure and Metal Binding Properties of a Poxvirus Resolvase.

H.Li, Y.Hwang, K.Perry, F.Bushman, G.D.Van Duyne.

ABSTRACT

Poxviruses replicate their linear genomes by forming concatemers that must be resolved into monomeric units to produce new virions. A viral resolvase cleaves DNA four-way junctions extruded at the concatemer junctions to produce monomeric genomes. This cleavage reaction is required for viral replication, so the resolvase is an attractive target for small molecule inhibitors. To provide a platform for understanding resolvase mechanism and designing inhibitors, we have determined the crystal structure of the canarypox virus (CPV) resolvase. CPV resolvase is dimer of RNase H superfamily domains related to Escherichia coli RuvC, with an active site lined by highly conserved acidic residues that bind metal ions. There are several intriguing structural differences between resolvase and RuvC, and a model of the CPV resolvase·Holliday junction complex provides insights into the consequences of these differences, including a plausible explanation for the weak sequence specificity exhibited by the poxvirus enzymes. The model also explains why the poxvirus resolvases are more promiscuous than RuvC, cleaving a variety of branched, bulged, and flap-containing substrates. Based on the unique active site structure observed for CPV resolvase, we have carried out a series of experiments to test divalent ion usage and preferences. We find that the two resolvase metal binding sites have different preferences for Mg(2+) versus Mn(2+) Optimal resolvase activity is maintained with 5 μm Mn(2+) and 100 μm Mg(2+), concentrations that are well below those required for either metal alone. Together, our findings provide biochemical insights and structural models that will facilitate studying poxvirus replication and the search for efficient poxvirus inhibitors.