The p190RhoGAP (GTPase-activating protein) proteins, p190RhoGAP-A (ARHGAP35) and p190RhoGAP-B (ARHGAP5)4-6, regulates Rho GTP hydrolysis and are important for proper Rho signalling. They share a domain organisation containing a GTP-binding GTPase domain, four FF domains, two GTPase-like folds (pG1 and pG2) in the middle domain and a C-terminal GAP domain. This entry represents pG1 and pG2 which are important for GAP activity toward RhoA and were classified as pseudoGTPases as they lack nucleotide-binding activity. Crystal structures revealed a small GTPase fold in both cases with a central 6-stranded beta-sheet surrounded by four alpha-helices [1].

1: p190RhoGAP proteins contain pseudoGTPase domains. Stiegler AL, Boggon TJ; Nat Commun. 2017;8:506. PMID:28894085