title: Molecular ruler determines needle length for the Salmonella Spi-1 injectisome.
abstract: The type-III secretion (T3S) systems of bacteria are part of self-assembling nanomachines: the bacterial flagellum that enables cells to propel themselves through liquid and across hydrated surfaces, and the injectisome that delivers pathogenic effector proteins into eukaryotic host cells. Although the flagellum and injectisome serve different purposes, they are evolutionarily related and share many structural similarities. Core features to these T3S systems are intrinsic length control mechanisms for external cellular projections: the hook of the flagellum and the injectisome needle. We present evidence that the Spi-1 injectisome, like the Salmonella flagellar hook, uses a secreted molecular ruler, InvJ, to determine needle length. This result supports a universal length control mechanism using molecular rulers for T3S systems.
authors.affiliation: Department of Biology, University of Utah, Salt Lake City, UT 84112 daniel.wee@utah.edu.
authors.forename: Daniel H
authors.identifier: http://orcid.org/0000-0002-1959-983X
authors.initials: DH
authors.lastname: Wee
authors.affiliation: Department of Biology, University of Utah, Salt Lake City, UT 84112.
authors.forename: Kelly T
authors.initials: KT
authors.lastname: Hughes
mesh_terms: D000483:Alleles; D000942:Antigens, Bacterial / Q000378:metabolism*; D001426:Bacterial Proteins / Q000378:metabolism*; D058947:Bacterial Secretion Systems; D002462:Cell Membrane / Q000378:metabolism; D002875:Chromosomes / Q000648:ultrastructure; D016000:Cluster Analysis; D003593:Cytoplasm / Q000378:metabolism; D004591:Electrophoresis, Polyacrylamide Gel; D005407:Flagella / Q000378:metabolism; D008854:Microscopy, Electron; D009154:Mutation; D009997:Osmotic Pressure; D019897:Periplasm / Q000378:metabolism; D017434:Protein Structure, Tertiary; D012486:Salmonella typhimurium / Q000378:metabolism*; D014774:Virulence
chemical_list: D000942:Antigens, Bacterial; D001426:Bacterial Proteins; D058947:Bacterial Secretion Systems; C419942:Spi1 protein, Salmonella; C093537:invJ protein, Salmonella typhimurium
keywords: Salmonella enterica; injectisome; length control; molecular ruler; type-III secretion