1uix

From Proteopedia

Coiled-coil structure of the RhoA-binding domain in Rho-kinase

Overview

Rho-kinase is a serine/threonine protein kinase that regulates, cytoskeletal events in cells. The enzyme activity of Rho-kinase is, auto-inhibited in the free state but is activated through direct binding, to the small GTPase Rho in the GTP-bound form. The crystal structure of, the Rho-binding domain (RhoBD) of Rho-kinase has been determined at 1.8-A, resolution by the multi-wavelength anomalous dispersion technique. The, structure shows that RhoBD dimerizes to form a parallel coiled-coil with, long consecutive alpha-helices extended to approximately 97 A and suggests, that free Rho-kinase can also form a dimer through parallel, self-association. At the middle region of the coiled-coil, the polypeptide, chains are flexible and display loose "knobs-into-holes" packing of the, side chains from both chains. RhoBD residues that have been shown to be, critical for Rho-binding are spread in the positively charged C-terminal, region. The parallel coiled-coil structure of our Rho-kinase RhoBD in the, free form is different from the anti-parallel coiled-coil structure of, RhoBD of protein kinase N when complexed with RhoA. Implications derived, from these structural studies in relation to the mechanism of Rho-kinase, activation will be addressed with previously reported experimental data.

About this Structure

1UIX is a Single protein structure of sequence from Bos taurus. Full crystallographic information is available from OCA.

Reference

Parallel coiled-coil association of the RhoA-binding domain in Rho-kinase., Shimizu T, Ihara K, Maesaki R, Amano M, Kaibuchi K, Hakoshima T, J Biol Chem. 2003 Nov 14;278(46):46046-51. Epub 2003 Sep 3. PMID:12954645

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