1sqk

From Proteopedia

Revision as of 00:27, 21 November 2007

CRYSTAL STRUCTURE OF CIBOULOT IN COMPLEX WITH SKELETAL ACTIN

Overview

The widespread beta-thymosin/WH2 actin binding domain has versatile, regulatory properties in actin dynamics and motility. beta-thymosins, (isolated WH2 domain) maintain monomeric actin in a "sequestered", nonpolymerizable form. In contrast, when repeated in tandem or inserted in, modular proteins, the beta-thymosin/WH2 domain promotes actin assembly at, filament barbed ends, like profilin. The structural basis for these, opposite functions is addressed using ciboulot, a three beta-thymosin, repeat protein. Only the first repeat binds actin and possesses the, function of ciboulot. The region that shows the strongest interaction with, actin is an amphipathic N-terminal alpha helix, present in all, beta-thymosin/WH2 domains, which recognizes the ATP bound actin structure, and uses the shear motion of actin linked to ATP hydrolysis to control, polymerization. Crystallographic ((1)H, (15)N), NMR, and mutagenetic data, reveal that the weaker interaction of the C-terminal region of, beta-thymosin/WH2 domain with actin accounts for the switch in function, from inhibition to promotion of actin assembly.

About this Structure

1SQK is a Protein complex structure of sequences from Drosophila melanogaster and Oryctolagus cuniculus with MG, ADP and LAR as ligands. Full crystallographic information is available from OCA.

Reference

The beta-thymosin/WH2 domain; structural basis for the switch from inhibition to promotion of actin assembly., Hertzog M, van Heijenoort C, Didry D, Gaudier M, Coutant J, Gigant B, Didelot G, Preat T, Knossow M, Guittet E, Carlier MF, Cell. 2004 May 28;117(5):611-23. PMID:15163409

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