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Publication Abstract from PubMed

Protein type III secretion systems (T3SSs) are organic nanosyringes that achieve an energy-dependent translocation of bacterial proteins through the two membranes of Gram-negative organisms. Examples include the pathogenic systems of animals, plants and symbiotic bacteria that inject factors into eukaryotic cells, and the flagellar export system that secretes flagellin. T3SSs possess a core of several membrane-associated proteins that are conserved across all known bacterial species that use this system. The Salmonella protein InvA is one of the most highly conserved proteins of this core of critical T3SS components. The crystal structure of a C-terminal domain of InvA reveals an unexpected homology to domains that have been repeatedly found as building blocks of other elements of the T3SS apparatus. This suggests the surprising hypothesis that evolution has produced a significant component of the apparatus structure through a series of gene-duplication and gene-rearrangement events.

A conserved domain in type III secretion links the cytoplasmic domain of InvA to elements of the basal body.,Lilic M, Quezada CM, Stebbins CE Acta Crystallogr D Biol Crystallogr. 2010 Jun;66(Pt 6):709-13. Epub 2010 May 15. PMID:20516623^[1]

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