%0 Journal Article
%T Crystal Structure of a Coiled-Coil Domain from Human ROCK I
%A Daqi Tu
%A Yiqun Li
%A Hyun Kyu Song
%A Angela V. Toms
%A Christopher J. Gould
%A Scott B. Ficarro
%A Jarrod A. Marto
%A Bruce L. Goode
%A Michael J. Eck
%J PLOS ONE
%D 2012
%I Public Library of Science (PLoS)
%R 10.1371/journal.pone.0018080
%X The small GTPase Rho and one of its targets, Rho-associated kinase (ROCK), participate in a variety of actin-based cellular processes including smooth muscle contraction, cell migration, and stress fiber formation. The ROCK protein consists of an N-terminal kinase domain, a central coiled-coil domain containing a Rho binding site, and a C-terminal pleckstrin homology domain. Here we present the crystal structure of a large section of the central coiled-coil domain of human ROCK I (amino acids 535¨C700). The structure forms a parallel ¦Á-helical coiled-coil dimer that is structurally similar to tropomyosin, an actin filament binding protein. There is an unusual discontinuity in the coiled-coil; three charged residues (E613, R617 and D620) are positioned at what is normally the hydrophobic core of coiled-coil packing. We speculate that this conserved irregularity could function as a hinge that allows ROCK to adopt its autoinhibited conformation.
%U http://www.plosone.org/article/info%3Adoi%2F10.1371%2Fjournal.pone.0018080