2c2a

From Proteopedia

Revision as of 15:50, 5 November 2007

STRUCTURE OF THE ENTIRE CYTOPLASMIC PORTION OF A SENSOR HISTIDINE KINASE PROTEIN

Overview

The large majority of histidine kinases (HKs) are multifunctional enzymes, having autokinase, phosphotransfer and phosphatase activities, and most of, these are transmembrane sensor proteins. Sensor HKs possess conserved, cytoplasmic phosphorylation and ATP-binding kinase domains. The different, enzymatic activities require participation by one or both of these, domains, implying the need for different conformational states. The, catalytic domains are linked to the membrane through a coiled-coil segment, that sometimes includes other domains. We describe here the first crystal, structure of the complete cytoplasmic region of a sensor HK, one from the, thermophile Thermotoga maritima in complex with ADPbetaN at 1.9 A, resolution. The structure reveals previously unidentified functions for, several conserved residues and reveals the relative disposition of domains, in a state seemingly poised for phosphotransfer. The structure thereby, inspires hypotheses for the mechanisms of autophosphorylation, phosphotransfer and response-regulator dephosphorylation, and for signal, transduction through the coiled-coil segment. Mutational tests support the, functional relevance of interdomain contacts.

About this Structure

2C2A is a Single protein structure of sequence from Thermotoga maritima with SO4 and ADP as ligands. Structure known Active Site: AC1. Full crystallographic information is available from OCA.

Reference

Structure of the entire cytoplasmic portion of a sensor histidine-kinase protein., Marina A, Waldburger CD, Hendrickson WA, EMBO J. 2005 Dec 21;24(24):4247-59. Epub 2005 Dec 1. PMID:16319927

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