Structural Biology

Crystal Clear

Science Signaling  15 Sep 2009:
Vol. 2, Issue 88, pp. ec305
DOI: 10.1126/scisignal.288ec305

Guanine nucleotide exchange factors (GEFs) stimulate exchange of guanine diphosphate (GDP) for guanine triphosphate (GTP) and activate small guanosine triphosphatases (GTPases) required for the regulation of many biological processes. Yang et al. provide a detailed picture of the complete catalytic cycle by which a GEF, DOCK9, activates the small GTPase Cdc42. A small region of DOCK9 appears to sense whether GTP or GDP is bound to Cdc42 in a mechanism that is distinct from that observed for other GTPases.

J. Yang, Z. Zhang, S. M. Roe, C. J. Marshall, D. Barford, Activation of Rho GTPases by DOCK exchange factors is mediated by a nucleotide sensor. Science 325, 1398–1402 (2009). [Abstract] [Full Text]