InterPro: IPR019093 Rac1-binding domain

The Rac1-binding domain is the C-terminal portion of YpkA from Yersinia. It is an all-helical molecule consisting of two distinct subdomains connected by a linker. The N-terminal end of this domain (residues 434-615) consists of six helices organised into two three-helix bundles packed against each other. This region is involved with binding to GTPases. The C-terminal end (residues 705-732) is a novel and elongated fold consisting of four helices clustered into two pairs, and this fold carries the helix implicated in actin activation. The Rac1-binding domain mimics host guanidine nucleotide dissociation inhibitors (GDIs) of the Rho GTPases, thereby inhibiting nucleotide exchange in Rac1 and causing cytoskeletal disruption in the host [1]. It is usually found downstream of IPR017442.