 The ROCK1 structure is a serine/threonine kinase with molecular weight of 158 kDa.It is a homodimer composed of a catalytic kinase domain (residues76-338) located at the amino or N-terminus of the protein, a coiled-coil region (residues 425-1100) containing the Rho-binding domain, and a pleckstrin-homology domain (residues 1118-1317) with a cysteine-rich domain.When a substrate is absent, ROCK1 is an autoinhibited loop structure.