Structural highlights
Function
SCTG_SALTY Involved in the synthesis of the type III secretion system (T3SS), also called injectisome, which is used to inject bacterial effector proteins into eukaryotic host cells (PubMed:9680224, PubMed:9786184). Pilot protein that is required for the proper localization of the secretin InvG/SctC in the outer membrane (PubMed:9680224, PubMed:9786184). Required for the secretion of the Sip virulence factors (PubMed:9680224, PubMed:23159244).[1] [2] [3]
Publication Abstract from PubMed
The type III secretion system (T3SS) is a multi-membrane-spanning protein channel used by Gram-negative pathogenic bacteria to secrete effectors directly into the host cell cytoplasm. In the many species reliant on the T3SS for pathogenicity, proper assembly of the outer membrane secretin pore depends on a diverse family of lipoproteins called pilotins. We present structural and biochemical data on the Salmonella enterica pilotin InvH and the S domain of its cognate secretin InvG. Characterization of InvH by X-ray crystallography revealed a dimerized, alpha-helical pilotin. Size-exclusion-coupled multi-angle light scattering and small-angle X-ray scattering provide supporting evidence for the formation of an InvH homodimer in solution. Structures of the InvH-InvG heterodimeric complex determined by X-ray crystallography and NMR spectroscopy indicate a predominantly hydrophobic interface. Knowledge of the interaction between InvH and InvG brings us closer to understanding the mechanisms by which pilotins assemble the secretin pore.
Characterization of the Pilotin-Secretin Complex from the Salmonella enterica Type III Secretion System Using Hybrid Structural Methods.,Majewski DD, Okon M, Heinkel F, Robb CS, Vuckovic M, McIntosh LP, Strynadka NCJ Structure. 2020 Aug 27. pii: S0969-2126(20)30288-4. doi:, 10.1016/j.str.2020.08.006. PMID:32877645[4]
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.
References
- ↑ Pati NB, Vishwakarma V, Jaiswal S, Periaswamy B, Hardt WD, Suar M. Deletion of invH gene in Salmonella enterica serovar Typhimurium limits the secretion of Sip effector proteins. Microbes Infect. 2013 Jan;15(1):66-73. PMID:23159244 doi:10.1016/j.micinf.2012.10.014
- ↑ Daefler S, Russel M. The Salmonella typhimurium InvH protein is an outer membrane lipoprotein required for the proper localization of InvG. Mol Microbiol. 1998 Jun;28(6):1367-80. PMID:9680224 doi:10.1046/j.1365-2958.1998.00908.x
- ↑ Crago AM, Koronakis V. Salmonella InvG forms a ring-like multimer that requires the InvH lipoprotein for outer membrane localization. Mol Microbiol. 1998 Oct;30(1):47-56. doi: 10.1046/j.1365-2958.1998.01036.x. PMID:9786184 doi:http://dx.doi.org/10.1046/j.1365-2958.1998.01036.x
- ↑ Majewski DD, Okon M, Heinkel F, Robb CS, Vuckovic M, McIntosh LP, Strynadka NCJ. Characterization of the Pilotin-Secretin Complex from the Salmonella enterica Type III Secretion System Using Hybrid Structural Methods. Structure. 2021 Feb 4;29(2):125-138.e5. PMID:32877645 doi:10.1016/j.str.2020.08.006
