title: A mortise-tenon joint in the transmembrane domain modulates autotransporter assembly into bacterial outer membranes.
abstract: Bacterial autotransporters comprise a 12-stranded membrane-embedded β-barrel domain, which must be folded in a process that entraps segments of an N-terminal passenger domain. This first stage of autotransporter folding determines whether subsequent translocation can deliver the N-terminal domain to its functional form on the bacterial cell surface. Here, paired glycine-aromatic 'mortise and tenon' motifs are shown to join neighbouring β-strands in the C-terminal barrel domain, and mutations within these motifs slow the rate and extent of passenger domain translocation to the surface of bacterial cells. In line with this, biophysical studies of the autotransporter Pet show that the conserved residues significantly quicken completion of the folding reaction and promote stability of the autotransporter barrel domain. Comparative genomics demonstrate conservation of glycine-aromatic residue pairings through evolution as a previously unrecognized feature of all autotransporter proteins.
authors: 1] Department of Microbiology, Monash University, Melbourne, Victoria 3800, Australia [2] Department of Biochemistry and Molecular Biology, Monash University, Melbourne, Victoria 3800, Australia.
authors: Denisse L
authors: DL
authors: Leyton
authors: Department of Biochemistry and Molecular Biology, Monash University, Melbourne, Victoria 3800, Australia.
authors: Matthew D
authors: MD
authors: Johnson
authors: 1] Department of Biochemistry and Molecular Biology, Monash University, Melbourne, Victoria 3800, Australia [2] School of Chemistry, Monash University, Melbourne, Victoria 3800, Australia.
authors: Rajiv
authors: R
authors: Thapa
authors: 1] Institut Pasteur, Molecular Genetics Unit, Departments of Microbiology and of Structural Biology and Chemistry, rue du Dr Roux, 75724 Paris Cedex 15, France [2] CNRS ERL3526, rue du Dr Roux, 75724 Paris Cedex 15, France.
authors: Gerard H M
authors: GH
authors: Huysmans
authors: Department of Microbiology, Monash University, Melbourne, Victoria 3800, Australia.
authors: Rhys A
authors: RA
authors: Dunstan
authors: Department of Microbiology, Monash University, Melbourne, Victoria 3800, Australia.
authors: Nermin
authors: N
authors: Celik
authors: 1] Department of Biochemistry and Molecular Biology, Monash University, Melbourne, Victoria 3800, Australia [2] School of Chemistry, Monash University, Melbourne, Victoria 3800, Australia.
authors: Hsin-Hui
authors: HH
authors: Shen
authors: Department of Biochemistry and Molecular Biology, Monash University, Melbourne, Victoria 3800, Australia.
authors: Dorothy
authors: D
authors: Loo
authors: Department of Microbiology, Monash University, Melbourne, Victoria 3800, Australia.
authors: Matthew J
authors: MJ
authors: Belousoff
authors: Department of Biochemistry and Molecular Biology, Monash University, Melbourne, Victoria 3800, Australia.
authors: Anthony W
authors: AW
authors: Purcell
authors: School of Immunity and Infection, University of Birmingham, Birmingham B15 2TT, UK.
authors: Ian R
authors: IR
authors: Henderson
authors: 1] Department of Biochemistry and Molecular Biology, Monash University, Melbourne, Victoria 3800, Australia [2] Department of Agriculture Sciences, La Trobe University, Melbourne, Victoria 3083, Australia.
authors: Travis
authors: T
authors: Beddoe
authors: Department of Biochemistry and Molecular Biology, Monash University, Melbourne, Victoria 3800, Australia.
authors: Jamie
authors: J
authors: Rossjohn
authors: School of Chemistry, Monash University, Melbourne, Victoria 3800, Australia.
authors: Lisandra L
authors: LL
authors: Martin
authors: Department of Microbiology and Immunology, The University of Melbourne, Melbourne, Victoria 3010, Australia.
authors: Richard A
authors: RA
authors: Strugnell
authors: Department of Microbiology, Monash University, Melbourne, Victoria 3800, Australia.
authors: Trevor
authors: T
authors: Lithgow
mesh_terms: D020816:Amino Acid Motifs; D000595:Amino Acid Sequence; D001425:Bacterial Outer Membrane Proteins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D001426:Bacterial Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D001427:Bacterial Toxins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D002265:Carboxylic Ester Hydrolases / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D002352:Carrier Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D017124:Conserved Sequence; D004768:Enterotoxins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D029968:Escherichia coli Proteins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D008958:Models, Molecular; D017510:Protein Folding; D017433:Protein Structure, Secondary; D017434:Protein Structure, Tertiary; D021381:Protein Transport; D011550:Pseudomonas aeruginosa / Q000235:genetics / Q000378:metabolism; D012697:Serine Endopeptidases / Q000737:chemistry / Q000235:genetics / Q000378:metabolism
chemical_list: D001425:Bacterial Outer Membrane Proteins; D001426:Bacterial Proteins; D001427:Bacterial Toxins; C090007:BrkA protein, Bordetella pertussis; D002352:Carrier Proteins; D004768:Enterotoxins; D029968:Escherichia coli Proteins; C017206:hemoglobin-binding protein, bacteria; D002265:Carboxylic Ester Hydrolases; C098953:EstA protein, bacteria; C107189:EspP protein, E coli; C530786:Pet protein, E coli; D012697:Serine Endopeptidases