PDBsum entry 4qgo

Hydrolase

PDB id: 4qgo

Contents

Protein chains

215 a.a.

Ligands

SO4 ×9

EDO ×2

Metals

_CL ×4

Waters ×654

PDB id:

4qgo

Name:

Hydrolase

Title:

Crystal structure of nuca from streptococcus agalactiae with no metal bound

Structure:

DNA-entry nuclease (competence-specific nuclease). Chain: a, b. Fragment: catalytic domain. Engineered: yes. Mutation: yes

Source:

Streptococcus agalactiae ilri112. Organism_taxid: 1318615. Gene: sail_8320. Expressed in: escherichia coli. Expression_system_taxid: 562

Resolution:

1.50Å R-factor: 0.154 R-free: 0.180

Authors:

L.C.Pedersen,A.F.Moon,P.Gaudu

Key ref:

A.F.Moon et al. (2014). Structural characterization of the virulence factor nuclease A from Streptococcus agalactiae. Acta Crystallogr D Biol Crystallogr, 70, 2937-2949. PubMed id: 25372684 DOI: 10.1107/S1399004714019725

Date:

23-May-14 Release date: 19-Nov-14

Protein chains

R5A2Y6  (R5A2Y6_STRAG) -

DOI no: 10.1107/S1399004714019725

Acta Crystallogr D Biol Crystallogr 70:2937-2949 (2014)

PubMed id: 25372684

Structural characterization of the virulence factor nuclease A from Streptococcus agalactiae.

A.F.Moon, P.Gaudu, L.C.Pedersen.

ABSTRACT

The group B pathogen Streptococcus agalactiae commonly populates the human gut and urogenital tract, and is a major cause of infection-based mortality in neonatal infants and in elderly or immunocompromised adults. Nuclease A (GBS_NucA), a secreted DNA/RNA nuclease, serves as a virulence factor for S. agalactiae, facilitating bacterial evasion of the human innate immune response. GBS_NucA efficiently degrades the DNA matrix component of neutrophil extracellular traps (NETs), which attempt to kill and clear invading bacteria during the early stages of infection. In order to better understand the mechanisms of DNA substrate binding and catalysis of GBS_NucA, the high-resolution structure of a catalytically inactive mutant (H148G) was solved by X-ray crystallography. Several mutants on the surface of GBS_NucA which might influence DNA substrate binding and catalysis were generated and evaluated using an imidazole chemical rescue technique. While several of these mutants severely inhibited nuclease activity, two mutants (K146R and Q183A) exhibited significantly increased activity. These structural and biochemical studies have greatly increased our understanding of the mechanism of action of GBS_NucA in bacterial virulence and may serve as a foundation for the structure-based drug design of antibacterial compounds targeted to S. agalactiae.