PDBsum entry 2zxp

Hydrolase

PDB id: 2zxp

Contents

Protein chain

648 a.a. *

Metals

_MN ×2

Waters ×293

* Residue conservation analysis

PDB id:

2zxp

Name:

Hydrolase

Title:

Crystal structure of recj in complex with mn2+ from thermus thermophilus hb8

Structure:

Single-stranded DNA specific exonuclease recj. Chain: a. Engineered: yes

Source:

Thermus thermophilus. Organism_taxid: 300852. Strain: hb8. Gene: recj, ttha1167. Expressed in: escherichia coli. Expression_system_taxid: 562.

Resolution:

2.30Å R-factor: 0.232 R-free: 0.281

Authors:

T.Wakamatsu,Y.Kitamura,N.Nakagawa,R.Masui,S.Kuramitsu

Key ref:

T.Wakamatsu et al. (2010). Structure of RecJ exonuclease defines its specificity for single-stranded DNA. J Biol Chem, 285, 9762-9769. PubMed id: 20129927

Date:

05-Jan-09 Release date: 05-Jan-10

Protein chain

Q5SJ47  (RECJ_THET8) -  Single-stranded-DNA-specific exonuclease RecJ from Thermus thermophilus (strain ATCC 27634 / DSM 579 / HB8)

Seq: 666 a.a.

Struc: 648 a.a.

Enzyme reactions

• Enzyme class: E.C.3.1.-.-

J Biol Chem 285:9762-9769 (2010)

PubMed id: 20129927

Structure of RecJ exonuclease defines its specificity for single-stranded DNA.

T.Wakamatsu, Y.Kitamura, Y.Kotera, N.Nakagawa, S.Kuramitsu, R.Masui.

ABSTRACT

RecJ is a single-stranded DNA (ssDNA)-specific 5'-3' exonuclease that plays an important role in DNA repair and recombination. To elucidate how RecJ achieves its high specificity for ssDNA, we determined the entire structures of RecJ both in a ligand-free form and in a complex with Mn(2+) or Mg(2+) by x-ray crystallography. The entire RecJ consists of four domains that form a molecule with an O-like structure. One of two newly identified domains had structural similarities to an oligonucleotide/oligosaccharide-binding (OB) fold. The OB fold domain alone could bind to DNA, indicating that this domain is a novel member of the OB fold superfamily. The truncated RecJ containing only the core domain exhibited much lower affinity for the ssDNA substrate compared with intact RecJ. These results support the hypothesis that these structural features allow specific binding of RecJ to ssDNA. In addition, the structure of the RecJ-Mn(2+) complex suggests that the hydrolysis reaction catalyzed by RecJ proceeds through a two-metal ion mechanism.