1mkp

From Proteopedia

Revision as of 16:06, 12 November 2007

CRYSTAL STRUCTURE OF PYST1 (MKP3)

Overview

The crystal structure of the catalytic domain from the MAPK phosphatase, Pyst1 (Pyst1-CD) has been determined at 2.35 A. The structure adopts a, protein tyrosine phosphatase (PTPase) fold with a shallow active site that, displays a distorted geometry in the absence of its substrate with some, similarity to the dual-specificity phosphatase cdc25. Functional, characterization of Pyst1-CD indicates it is sufficient to dephosphorylate, activated ERK2 in vitro. Kinetic analysis of Pyst1 and Pyst1-CD using the, substrate p-nitrophenyl phosphate (pNPP) reveals that both molecules, undergo catalytic activation in the presence of recombinant inactive ERK2, switching from a low- to high-activity form. Mutation of Asp 262, located, 5.5 A distal to the active site, demonstrates it is essential for, catalysis in the high-activity ERK2-dependent conformation of Pyst1 but, not for the low-activity ERK2-independent form, suggesting that ERK2, induces closure of the Asp 262 loop over the active site, thereby, enhancing Pyst1 catalytic efficiency.

About this Structure

1MKP is a Single protein structure of sequence from Homo sapiens with CL and MPD as ligands. Full crystallographic information is available from OCA.

Reference

Crystal structure of the MAPK phosphatase Pyst1 catalytic domain and implications for regulated activation., Stewart AE, Dowd S, Keyse SM, McDonald NQ, Nat Struct Biol. 1999 Feb;6(2):174-81. PMID:10048930

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