2BNX

Crystal structure of the dimeric regulatory domain of mouse diaphaneous-related formin (DRF), mDia1

Summary for 2BNX

• Entry DOI: 10.2210/pdb2bnx/pdb
• Related: 1V9D
• Descriptor: DIAPHANOUS PROTEIN HOMOLOG 1, CHLORIDE ION (3 entities in total)
• Functional Keywords: autoinhibition, actin, nucleation, cytoskeleton, structural protein
• Biological source: MUS MUSCULUS (MOUSE)
• Total number of polymer chains: 2
• Total formula weight: 89225.54

Authors

Otomo, T.,Otomo, C.,Tomchick, D.R.,Machius, M.,Rosen, M.K. (deposition date: 2005-04-05, release date: 2005-06-13, Last modification date: 2024-05-08)

Primary citation

Otomo, T.,Otomo, C.,Tomchick, D.R.,Machius, M.,Rosen, M.K.
Structural Basis of Rho Gtpase-Mediated Activation of the Formin Mdia1
Mol.Cell, 18:273-, 2005

PubMed Abstract: Diaphanous-related formins (DRFs) regulate dynamics of unbranched actin filaments during cell contraction and cytokinesis. DRFs are autoinhibited through intramolecular binding of a Diaphanous autoinhibitory domain (DAD) to a conserved N-terminal regulatory element. Autoinhibition is relieved through binding of the GTPase RhoA to the N-terminal element. We report the crystal structure of the dimeric regulatory domain of the DRF, mDia1. Dimerization is mediated by an intertwined six-helix bundle, from which extend two Diaphanous inhibitory domains (DIDs) composed of five armadillo repeats. NMR and biochemical mapping indicate the RhoA and DAD binding sites on the DID partially overlap, explaining activation of mDia1 by the GTPase. RhoA binding also requires an additional structurally independent segment adjacent to the DID. This regulatory construction, involving a GTPase binding site spanning a flexibly tethered arm and the inhibitory module, is observed in many autoinhibited effectors of Ras superfamily GTPases, suggesting evolutionary pressure for this design.

PubMed: 15866170
DOI: 10.1016/J.MOLCEL.2005.04.002

Experimental method

X-RAY DIFFRACTION (2.4 Å)