Osman Salih / Han Remaut / Gabriel Waksman / Elena V Orlova /
PubMed 要旨
Bacterial pili are important virulence factors involved in host cell attachment and/or biofilm formation, key steps in establishing and maintaining successful infection. Here we studied Salmonella ...Bacterial pili are important virulence factors involved in host cell attachment and/or biofilm formation, key steps in establishing and maintaining successful infection. Here we studied Salmonella atypical fimbriae (or Saf pili), formed by the conserved chaperone/usher pathway. In contrast to the well-established quaternary structure of typical/FGS-chaperone assembled, rod-shaped, chaperone/usher pili, little is known about the supramolecular organisation in atypical/FGL-chaperone assembled fimbriae. In our study, we have used negative stain electron microscopy and single-particle image analysis to determine the three-dimensional structure of the Salmonella typhimurium Saf pilus. Our results show atypical/FGL-chaperone assembled fimbriae are composed of highly flexible linear multi-subunit fibres that are formed by globular subunits connected to each other by short links giving a "beads on a string"-like appearance. Quantitative fitting of the atomic structure of the SafA pilus subunit into the electron density maps, in combination with linker modelling and energy minimisation, has enabled analysis of subunit arrangement and intersubunit interactions in the Saf pilus. Short intersubunit linker regions provide the molecular basis for flexibility of the Saf pilus by acting as molecular hinges allowing a large range of movement between consecutive subunits in the fibre.
EMDB-1494: Structural Analysis of the Saf Pilus by Electron Microscopy and Image Processing. 3D reconstruction of the Type A Saf pilus, one of two conformations of the pilus refined. PDB-3cre: Electron Microscopy model of the Saf Pilus- Type A 手法: EM (単粒子) / 解像度: 17.0 Å
EMDB-1495: Structural Analysis of the Saf Pilus by Electron Microscopy and Image Processing. 3D reconstruction of the Type B Saf pilus, one of two conformations of the pilus refined. PDB-3crf: Electron Microscopy model of the Saf Pilus- Type B 手法: EM (単粒子) / 解像度: 17.0 Å
由来
Salmonella enterica subsp. enterica serovar Typhimurium str. LT2 (サルモネラ菌)
salmonella typhimurium (サルモネラ菌)
キーワード
MEMBRANE PROTEIN / SafA protein polymer / Type A Saf Pilus / Fibril Protein / Type B Saf Pilus