3CXB

Crystal Structure of sifa and skip

Summary for 3CXB

• Entry DOI: 10.2210/pdb3cxb/pdb
• Descriptor: Protein sifA, Pleckstrin homology domain-containing family M member 2 (3 entities in total)
• Functional Keywords: sifa, skip, complex, virulence, cytoplasm, membrane, polymorphism, signaling protein
• Biological source: Salmonella typhimurium; More
• Cellular location: Secreted: Q56061; Cytoplasm: Q8IWE5
• Total number of polymer chains: 2
• Total formula weight: 50915.44

Authors

Huang, Z.,Chai, J. (deposition date: 2008-04-24, release date: 2008-12-02, Last modification date: 2024-03-20)

Primary citation

Ohlson, M.B.,Huang, Z.,Alto, N.M.,Blanc, M.P.,Dixon, J.E.,Chai, J.,Miller, S.I.
Structure and function of Salmonella SifA indicate that its interactions with SKIP, SseJ, and RhoA family GTPases induce endosomal tubulation
Cell Host Microbe, 4:434-446, 2008

PubMed Abstract: The Salmonella typhimurium type III secretion effector protein SifA is essential for inducing tubulation of the Salmonella phagosome and binds the mammalian kinesin-binding protein SKIP. Coexpression of SifA with the effector SseJ induced tubulation of mammalian cell endosomes, similar to that induced by Salmonella infection. Interestingly, GTP-bound RhoA, RhoB, and RhoC also induced endosomal tubulation when coexpressed with SseJ, indicating that SifA likely mimics or activates a RhoA family GTPase. The structure of SifA in complex with the PH domain of SKIP revealed that SifA has two distinct domains; the amino terminus binds SKIP, and the carboxyl terminus has a fold similar to SopE, a Salmonella effector with Rho GTPase guanine nucleotide exchange factor activity (GEF). Similar to GEFs, SifA interacted with GDP-bound RhoA, and purified SseJ and RhoA formed a protein complex, suggesting that SifA, SKIP, SseJ, and RhoA family GTPases cooperatively promote host membrane tubulation.

PubMed: 18996344
DOI: 10.1016/j.chom.2008.08.012

Experimental method

X-RAY DIFFRACTION (2.6 Å)