2YIN | pdb_00002yin

Multiple Factors Confer Specific Cdc42 and Rac Protein Activation by Dedicator of Cytokinesis (Dock) Nucleotide Exchange Factors.

(2011) J Biological Chem&nbsp286: 25341

• PubMed:&nbsp21613211&nbspSearch on PubMedSearch on PubMed Central
• DOI:&nbsphttps://doi.org/10.1074/jbc.M111.236455
• Primary Citation of Related Structures: &nbsp
  2YIN


• PubMed Abstract:&nbsp
  

  DOCK (dedicator of cytokinesis) guanine nucleotide exchange factors (GEFs) activate the Rho-family GTPases Rac and Cdc42 to control cell migration, morphogenesis, and phagocytosis. The DOCK A and B subfamilies activate Rac, whereas the DOCK D subfamily activates Cdc42. Nucleotide exchange is catalyzed by a conserved DHR2 domain (DOCK(DHR2)). Although the molecular basis for DOCK(DHR2)-mediated GTPase activation has been elucidated through structures of a DOCK9(DHR2)-Cdc42 complex, the factors determining recognition of specific GTPases are unknown. To understand the molecular basis for DOCK-GTPase specificity, we have determined the crystal structure of DOCK2(DHR2) in complex with Rac1. DOCK2(DHR2) and DOCK9(DHR2) exhibit similar tertiary structures and homodimer interfaces and share a conserved GTPase-activating mechanism. Multiple structural differences between DOCK2(DHR2) and DOCK9(DHR2) account for their selectivity toward Rac1 and Cdc42. Key determinants of selectivity of Cdc42 and Rac for their cognate DOCK(DHR2) are a Phe or Trp residue within β3 (residue 56) and the ability of DOCK proteins to exploit differences in the GEF-induced conformational changes of switch 1 dependent on a divergent residue at position 27. DOCK proteins, therefore, differ from DH-PH GEFs that select their cognate GTPases through recognition of structural differences within the β2/β3 strands.

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Organizational Affiliation:&nbsp
• Section of Structural Biology, Institute of Cancer Research, Chester Beatty Laboratories, 237 Fulham Road, London SW3 6JB, United Kingdom.