Flagellar filament of bacteria


R vs. L formsR vs. L forms

Quoted from [1]:

"The bacterial flagellar filament is a helical propeller rotated by the flagellar motor for bacterial locomotion. The filament is a supercoiled assembly of a single protein, flagellin, and is formed by 11 protofilaments. For bacterial taxis, the reversal of motor rotation switches the supercoil between left- and right-handed, both of which arise from combinations of two distinct conformations and packing interactions of the L-type and R-type protofilaments."

The structure of a straight R form of the flagellar filament was reported in 2003[2], by fitting a crystallographic model of the monomer[3] into an electron cryomicroscopic density map with resolution approaching 4 Å. The resulting full-length R form monomer, 1ucu, included terminal alpha helices that were absent in the crystallographic model.

The structure of a straight L form of the flagellar filament was reported in 2010[1]. The monomer, 3a5x, was obtained by fitting the R-form monomer 1ucu into the electron cryomicroscopy density map.

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  • R to L Monomer Morph (all residues aligned) ()[4]

NotesNotes

  1. 1.0 1.1 Maki-Yonekura, S., K. Yonekura, & K. Namba, 'Conformational change of flagellin for polymorphic supercoiling of the flagellar filament', Nat. Struct. Mol. Biol. 17, 417–422 (2010). doi:10.1038/nsmb.1774
  2. Yonekura K, Maki-Yonekura S, Namba K. Complete atomic model of the bacterial flagellar filament by electron cryomicroscopy. Nature. 2003 Aug 7;424(6949):643-50. PMID:12904785 doi:http://dx.doi.org/10.1038/nature01830
  3. Samatey FA, Imada K, Nagashima S, Vonderviszt F, Kumasaka T, Yamamoto M, Namba K. Structure of the bacterial flagellar protofilament and implications for a switch for supercoiling. Nature. 2001 Mar 15;410(6826):331-7. PMID:11268201 doi:10.1038/35066504
  4. Chemically possible morph generated by the Yale Morph Server (molmovdb.org), 1ucu to 3a5x.

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