A mortise-tenon joint in the transmembrane domain modulates autotransporter assembly into bacterial outer membranes

Research output: Contribution to journalArticle

Authors

  • Matthew D Johnson
  • Rajiv Thapa
  • Gerard H M Huysmans
  • Rhys A Dunstan
  • Nermin Celik
  • Hsin-Hui Shen
  • Dorothy Loo
  • Matthew J Belousoff
  • Anthony W Purcell
  • Travis Beddoe
  • Jamie Rossjohn
  • Lisandra L Martin
  • Richard A Strugnell
  • Trevor Lithgow

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.

Details

Original languageEnglish
Pages (from-to)4239
Number of pages11
JournalNature Communications
Volume5
Publication statusPublished - 26 Jun 2014

Keywords

  • Amino Acid Motifs, Amino Acid Sequence, Bacterial Outer Membrane Proteins, Bacterial Proteins, Bacterial Toxins, Carboxylic Ester Hydrolases, Carrier Proteins, Conserved Sequence, Enterotoxins, Escherichia coli Proteins, Models, Molecular, Protein Folding, Protein Structure, Secondary, Protein Structure, Tertiary, Protein Transport, Pseudomonas aeruginosa, Serine Endopeptidases