PDBsum entry 2myt

Oxidoreductase

PDB id: 2myt

Contents

Protein chain

131 a.a.

PDB id:

2myt

Name:

Oxidoreductase

Title:

An arsenate reductase in the intermediate state

Structure:

Glutaredoxin arsenate reductase. Chain: a. Synonym: low molecular weight protein-tyrosine-phosphatase, protein arsc, synarsc, rsynarsc. Engineered: yes. Mutation: yes

Source:

Synechocystis sp.. Organism_taxid: 1111708. Strain: pcc 6803. Gene: arsc, slr0946. Expressed in: escherichia coli. Expression_system_taxid: 562.

NMR struc:

20 models

Authors:

C.Jin,C.Yu,C.Hu,Y.Hu

Key ref:

C.Hu et al. (2015). A Hybrid Mechanism for the Synechocystis Arsenate Reductase Revealed by Structural Snapshots during Arsenate Reduction. J Biol Chem, 290, 22262-22273. PubMed id: 26224634 DOI: 10.1074/jbc.M115.659896

Date:

30-Jan-15 Release date: 05-Aug-15

Protein chain

P74313  (ARSC_SYNY3) -  Glutaredoxin arsenate reductase from Synechocystis sp. (strain ATCC 27184 / PCC 6803 / Kazusa)

Seq: 131 a.a.

Struc: 131 a.a.*

* PDB and UniProt seqs differ at 3 residue positions (black crosses)

Enzyme reactions

• Enzyme class 2: E.C.1.20.4.1 - arsenate reductase (glutathione/glutaredoxin).
• Reaction: [glutaredoxin]-dithiol + arsenate + glutathione + H⁺ = glutathionyl-S- S-[glutaredoxin] + arsenite + H2O
• Cofactor: Mo cation
• Enzyme class 3: E.C.3.1.3.48 - protein-tyrosine-phosphatase.
• Reaction: O-phospho-L-tyrosyl-[protein] + H2O = L-tyrosyl-[protein] + phosphate

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: 10.1074/jbc.M115.659896

J Biol Chem 290:22262-22273 (2015)

PubMed id: 26224634

A Hybrid Mechanism for the Synechocystis Arsenate Reductase Revealed by Structural Snapshots during Arsenate Reduction.

C.Hu, C.Yu, Y.Liu, X.Hou, X.Liu, Y.Hu, C.Jin.

ABSTRACT

Evolution of enzymes plays a crucial role in obtaining new biological functions for all life forms. Arsenate reductases (ArsC) are several families of arsenic detoxification enzymes that reduce arsenate to arsenite, which can subsequently be extruded from cells by specific transporters. Among these, the Synechocystis ArsC (SynArsC) is structurally homologous to the well characterized thioredoxin (Trx)-coupled ArsC family but requires the glutaredoxin (Grx) system for its reactivation, therefore classified as a unique Trx/Grx-hybrid family. The detailed catalytic mechanism of SynArsC is unclear and how the "hybrid" mechanism evolved remains enigmatic. Herein, we report the molecular mechanism of SynArsC by biochemical and structural studies. Our work demonstrates that arsenate reduction is carried out via an intramolecular thiol-disulfide cascade similar to the Trx-coupled family, whereas the enzyme reactivation step is diverted to the coupling of the glutathione-Grx pathway due to the local structural difference. The current results support the hypothesis that SynArsC is likely a molecular fossil representing an intermediate stage during the evolution of the Trx-coupled ArsC family from the low molecular weight protein phosphotyrosine phosphatase (LMW-PTPase) family.