InterPro domain: IPR000198

Members of the Rho family of small G proteins transduce signals from plasma-membranereceptors and control cell adhesion, motility and shape by actin cytoskeleton formation.Like all other GTPases, Rho proteins act as molecular switches, with an activeGTP-bound form and an inactive GDP-bound form. The active conformation is promoted byguanine-nucleotide exchange factors, and the inactive state by GTPase-activating proteins(GAPs) which stimulate the intrinsic GTPase activity of small G proteins.This entry is a Rho/Rac/Cdc42-like GAP domain, that is found in a wide variety of large,multi-functional proteins [ 1 ].A number of structure are known for this family[ 2 , 2 , 3 ].The domain is composed of seven alpha helices.This domain is also known as the breakpoint cluster region-homology (BH) domain.

1. The structure of the GTPase-activating domain from p50rhoGAP. Nature 385, 458-61
2. Crystal structure of the breakpoint cluster region-homology domain from phosphoinositide 3-kinase p85 alpha subunit. Proc. Natl. Acad. Sci. U.S.A. 93, 14373-8
3. Crystal structure of a small G protein in complex with the GTPase-activating protein rhoGAP. Nature 388, 693-7