title: Channel-tunnels.
abstract: TolC and its many homologues comprise an alpha-helical transperiplasmic tunnel embedded in the bacterial outer membrane by a contiguous beta-barrel channel, providing a large exit duct for diverse substrates. The 'channel-tunnel' is closed at its periplasmic entrance, but can be opened by an 'iris-like' mechanism when recruited by substrate-engaged proteins in the cytosolic membrane.
authors.affiliation: Department of Pathology, Cambridge University, Tennis Court Road, Cambridge CB2 1QP, UK. vk103@mole.bio.cam.ac.uk
authors.forename: V
authors.initials: V
authors.lastname: Koronakis
authors.forename: C
authors.initials: C
authors.lastname: Andersen
authors.forename: C
authors.initials: C
authors.lastname: Hughes
mesh_terms: D001425:Bacterial Outer Membrane Proteins / Q000737:chemistry* / Q000378:metabolism / Q000502:physiology / Q000648:ultrastructure; D018360:Crystallography, X-Ray; D004926:Escherichia coli / Q000378:metabolism; D029968:Escherichia coli Proteins; D026901:Membrane Transport Proteins; D008854:Microscopy, Electron; D008958:Models, Molecular; D011487:Protein Conformation; D017433:Protein Structure, Secondary; D021381:Protein Transport
chemical_list: D001425:Bacterial Outer Membrane Proteins; D029968:Escherichia coli Proteins; D026901:Membrane Transport Proteins; C073126:tolC protein, E coli