A low molecular weight protein tyrosine phosphatase from Synechocystis sp. strain PCC 6803: enzymatic characterization and identification of its potential substrates.

ABSTRACT: The predicted protein product of open reading frame slr0328 from Synechocystis sp. PCC 6803, SynPTP, possesses significant amino acid sequence similarity with known low molecular weight protein tyrosine phosphatases (PTPs). To determine the functional properties of this hypothetical protein, open reading frame slr0328 was expressed in Escherichia coli. The purified recombinant protein, SynPTP, displayed its catalytic phosphatase activity towards several tyrosine, but not serine, phosphorylated exogenous protein substrates. The protein phosphatase activity of SynPTP was inhibited by sodium orthovanadate, a known inhibitor of tyrosine phosphatases, but not by okadaic acid, an inhibitor for many serine/threonine phosphatases. Kinetic analysis indicated that the K(m) and V(max) values for SynP

SUBMITTER: Mukhopadhyay A 

PROVIDER: S-EPMC3115683 | biostudies-literature | 2011 May

REPOSITORIES: biostudies-literature