1g4u

Publication Abstract from PubMed

Salmonella spp. utilize a specialized protein secretion system to deliver a battery of effector proteins into host cells. Several of these effectors stimulate Cdc42- and Rac1-dependent cytoskeletal changes that promote bacterial internalization. These potentially cytotoxic alterations are rapidly reversed by the effector SptP, a tyrosine phosphatase and GTPase activating protein (GAP) that targets Cdc42 and Rac1. The 2.3 A resolution crystal structure of an SptP-Rac1 transition state complex reveals an unusual GAP architecture that mimics host functional homologs. The phosphatase domain possesses a conserved active site but distinct surface properties. Binding to Rac1 induces a dramatic stabilization in SptP of a four-helix bundle that makes extensive contacts with the Switch I and Switch II regions of the GTPase.

Modulation of host signaling by a bacterial mimic: structure of the Salmonella effector SptP bound to Rac1.,Stebbins CE, Galan JE Mol Cell. 2000 Dec;6(6):1449-60. PMID:11163217^[1]

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.