title: Ushers and secretins: channels for the secretion of folded proteins across the bacterial outer membrane.
abstract: Gram-negative bacteria have evolved a number of pathways for extracellular protein secretion. Proteins targeted for secretion in Gram-negative bacteria must cross the outer membrane in addition to the cytoplasmic membrane. This must be accomplished without compromising the barrier properties of the outer membrane and is further complicated by the fact that proteins may fold prior to secretion outside the cell. This review will discuss the usher and secretin families of integral outer membrane proteins, which function to allow the secretion of folded proteins in Gram-negative bacteria.
authors.affiliation: Center for Infectious Diseases, Department of Molecular Genetics and Microbiology, State University of New York at Stony Brook, 11794-5120, USA. dthanassi@ms.cc.sunysb.edu
authors.forename: David G
authors.initials: DG
authors.lastname: Thanassi
mesh_terms: D001425:Bacterial Outer Membrane Proteins / Q000235:genetics / Q000502:physiology*; D001426:Bacterial Proteins / Q000737:chemistry / Q000378:metabolism*; D002462:Cell Membrane / Q000502:physiology; D010861:Fimbriae, Bacterial / Q000502:physiology; D005798:Genes, Bacterial; D006090:Gram-Negative Bacteria / Q000235:genetics / Q000502:physiology*; D008954:Models, Biological; D018832:Molecular Chaperones / Q000235:genetics / Q000502:physiology; D015394:Molecular Structure; D017510:Protein Folding
chemical_list: D001425:Bacterial Outer Membrane Proteins; D001426:Bacterial Proteins; D018832:Molecular Chaperones