Crystal Structure of ROCK I bound to Y-27632

Experimental Data Snapshot

  • Resolution: 2.60 Å
  • R-Value Free: 0.266 
  • R-Value Work: 0.251 
  • R-Value Observed: 0.252 

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The Structure of Dimeric ROCK I Reveals the Mechanism for Ligand Selectivity.

Jacobs, M.Hayakawa, K.Swenson, L.Bellon, S.Fleming, M.Taslimi, P.Doran, J.

(2006) J Biol Chem 281: 260-268

  • DOI: https://doi.org/10.1074/jbc.M508847200
  • Primary Citation of Related Structures:  
    2ERZ, 2ESM, 2ETK, 2ETR, 3D9V

  • PubMed Abstract: 

    ROCK or Rho-associated kinase, a serine/threonine kinase, is an effector of Rho-dependent signaling and is involved in actin-cytoskeleton assembly and cell motility and contraction. The ROCK protein consists of several domains: an N-terminal region, a kinase catalytic domain, a coiled-coil domain containing a RhoA binding site, and a pleckstrin homology domain. The C-terminal region of ROCK binds to and inhibits the kinase catalytic domains, and this inhibition is reversed by binding RhoA, a small GTPase. Here we present the structure of the N-terminal region and the kinase domain. In our structure, two N-terminal regions interact to form a dimerization domain linking two kinase domains together. This spatial arrangement presents the kinase active sites and regulatory sequences on a common face affording the possibility of both kinases simultaneously interacting with a dimeric inhibitory domain or with a dimeric substrate. The kinase domain adopts a catalytically competent conformation; however, no phosphorylation of active site residues is observed in the structure. We also determined the structures of ROCK bound to four different ATP-competitive small molecule inhibitors (Y-27632, fasudil, hydroxyfasudil, and H-1152P). Each of these compounds binds with reduced affinity to cAMP-dependent kinase (PKA), a highly homologous kinase. Subtle differences exist between the ROCK- and PKA-bound conformations of the inhibitors that suggest that interactions with a single amino acid of the active site (Ala215 in ROCK and Thr183 in PKA) determine the relative selectivity of these compounds. Hydroxyfasudil, a metabolite of fasudil, may be selective for ROCK over PKA through a reversed binding orientation.

  • Organizational Affiliation

    Vertex Pharmaceuticals Incorporated, Cambridge, Massachusetts 02139, USA. marc_jacobs@vrtx.com

Find similar proteins by:  (by identity cutoff)  |  3D Structure
Entity ID: 1
MoleculeChains Sequence LengthOrganismDetailsImage
Rho-associated protein kinase 1
A, B
415Homo sapiensMutation(s): 0 
Gene Names: ROCK1
EC: (PDB Primary Data), (UniProt)
UniProt & NIH Common Fund Data Resources
Find proteins for Q13464 (Homo sapiens)
Explore Q13464 
Go to UniProtKB:  Q13464
PHAROS:  Q13464
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupQ13464
Sequence Annotations
  • Reference Sequence
Small Molecules
Ligands 1 Unique
IDChains Name / Formula / InChI Key2D Diagram3D Interactions
Query on Y27

Download Ideal Coordinates CCD File 
C [auth A],
D [auth B]
C14 H21 N3 O
Binding Affinity Annotations 
IDSourceBinding Affinity
Y27 BindingDB:  2ETR Ki: min: 25.12, max: 220 (nM) from 5 assay(s)
IC50: min: 46, max: 1130 (nM) from 6 assay(s)
PDBBind:  2ETR Ki: 150 (nM) from 1 assay(s)
Experimental Data & Validation

Experimental Data

  • Resolution: 2.60 Å
  • R-Value Free: 0.266 
  • R-Value Work: 0.251 
  • R-Value Observed: 0.252 
  • Space Group: P 31 2 1
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 180.865α = 90
b = 180.865β = 90
c = 91.456γ = 120
Software Package:
Software NamePurpose
DENZOdata reduction
SCALEPACKdata scaling
PDB_EXTRACTdata extraction

Structure Validation

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Ligand Structure Quality Assessment 

Entry History 

Deposition Data

  • Released Date: 2005-11-08 
  • Deposition Author(s): Jacobs, M.

Revision History  (Full details and data files)

  • Version 1.0: 2005-11-08
    Type: Initial release
  • Version 1.1: 2008-05-01
    Changes: Version format compliance
  • Version 1.2: 2011-07-13
    Changes: Version format compliance
  • Version 1.3: 2017-10-18
    Changes: Refinement description
  • Version 1.4: 2023-08-23
    Changes: Data collection, Database references, Derived calculations, Refinement description