3BRW

Structure of the Rap-RapGAP complex

Summary for 3BRW

• Entry DOI: 10.2210/pdb3brw/pdb
• Related: 1SRQ
• Descriptor: Rap1 GTPase-activating protein 1, Ras-related protein Rap-1b, MAGNESIUM ION, ... (6 entities in total)
• Functional Keywords: gap, g proteins, gtpase, rap, gtpase activation, gtp-binding, gtp binding protein
• Biological source: Homo sapiens (human); More
• Cellular location: Golgi apparatus membrane; Peripheral membrane protein: P47736; Cell membrane: P61224
• Total number of polymer chains: 4
• Total formula weight: 136257.77

Authors

Scrima, A.,Thomas, C.,Deaconescu, D.,Wittinghofer, A. (deposition date: 2007-12-21, release date: 2008-03-11, Last modification date: 2023-11-01)

Primary citation

Scrima, A.,Thomas, C.,Deaconescu, D.,Wittinghofer, A.
The Rap-RapGAP complex: GTP hydrolysis without catalytic glutamine and arginine residues
Embo J., 27:1145-1153, 2008

PubMed Abstract: The GTP-binding protein Rap1 regulates integrin-mediated and other cell adhesion processes. Unlike most other Ras-related proteins, it contains a threonine in switch II instead of a glutamine (Gln61 in Ras), a residue crucial for the GTPase reaction of most G proteins. Furthermore, unlike most other GTPase-activating proteins (GAPs) for small G proteins, which supply a catalytically important Arg-finger, no arginine residue of RapGAP makes a significant contribution to the GTPase reaction of Rap1. For a detailed understanding of the reaction mechanism, we have solved the structure of Rap1 in complex with Rap1GAP. It shows that the Thr61 of Rap is away from the active site and that an invariant asparagine of RapGAPs, the Asn-thumb, takes over the role of the cis-glutamine of Ras, Rho or Ran. The structure and biochemical data allow to further explain the mechanism and to define the important role of a conserved tyrosine. The structure and biochemical data furthermore show that the RapGAP homologous region of the tumour suppressor Tuberin is sufficient for catalysis on Rheb.

PubMed: 18309292
DOI: 10.1038/emboj.2008.30

Experimental method

X-RAY DIFFRACTION (3.4 Å)