Structural highlights
3o02 is a 2 chain structure with sequence from "bacillus_typhimurium"_loeffler_1892 "bacillus typhimurium" loeffler 1892. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance.
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| Ligands: | , |
| Related: | 3nzz, 3o00, 3o01 |
| Gene: | sipD, sspD, STM2883 ("Bacillus typhimurium" Loeffler 1892) |
| Resources: | FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT |
Function
[SIPD_SALTY] Required for translocation of effector proteins via the type III secretion system SPI-1, which is essential for an efficient bacterial internalization. Probably acts by modulating the secretion of SipA, SipB, and SipC.[1] [2]
Publication Abstract from PubMed
The type III secretion system (T3SS) is a protein injection nanomachinery required for virulence by many human pathogenic bacteria including Salmonella and Shigella. An essential component of the T3SS is the tip protein and the Salmonella SipD and the Shigella IpaD tip proteins interact with bile salts, which serve as environmental sensors for these enteric pathogens. SipD and IpaD have long central coiled coils and their N-terminal regions form alpha-helical hairpins and a short helix alpha3 that pack against the coiled coil. Using AutoDock, others have predicted that the bile salt deoxycholate binds IpaD in a cleft formed by the alpha-helical hairpin and its long central coiled coil. NMR chemical shift mapping, however, indicated that the SipD residues most affected by bile salts are located in a disordered region near helix alpha3. Thus, how bile salts interact with SipD and IpaD is unclear. Here, we report the crystal structures of SipD in complex with the bile salts deoxycholate and chenodeoxycholate. Bile salts bind SipD in a region different from what was predicted for IpaD. In SipD, bile salts bind part of helix alpha3 and the C-terminus of the long central coiled coil, towards the C-terminus of the protein. We discuss the biological implication of the differences in how bile salts interact with SipD and IpaD.
The crystal structures of the Salmonella type III secretion system tip protein SipD in complex with deoxycholate and chenodeoxycholate.,Chatterjee S, Zhong D, Nordhues BA, Battaile KP, Lovell SW, De Guzman RN Protein Sci. 2010 Oct 28. PMID:21031487[3]
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.
References
- ↑ Kaniga K, Trollinger D, Galan JE. Identification of two targets of the type III protein secretion system encoded by the inv and spa loci of Salmonella typhimurium that have homology to the Shigella IpaD and IpaA proteins. J Bacteriol. 1995 Dec;177(24):7078-85. PMID:8522512
- ↑ Collazo CM, Galan JE. The invasion-associated type III system of Salmonella typhimurium directs the translocation of Sip proteins into the host cell. Mol Microbiol. 1997 May;24(4):747-56. PMID:9194702
- ↑ Chatterjee S, Zhong D, Nordhues BA, Battaile KP, Lovell SW, De Guzman RN. The crystal structures of the Salmonella type III secretion system tip protein SipD in complex with deoxycholate and chenodeoxycholate. Protein Sci. 2010 Oct 28. PMID:21031487 doi:10.1002/pro.537
