Flagellar filament of bacteria

From Proteopedia

R vs. L forms

Quoted from Maki-Yonekura, Yonekura and Namba, 2010^[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."^[1]

The structure of a straight R form of the flagellar filament was reported in 2003^[2], by fitting and extending a crystallographic model of the monomer (1io1)^[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 L form electron cryomicroscopy density map.

R to L Morphs

Below are morphs between the R and L forms of the monomer (1ucu and 3a5x respectively) and the filament. Filament models were kindly provided by T. Fujii and K. Namba.

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

• ^[5]

• (Filament morphs are in preparation. Eric Martz 07:10, 15 May 2011 (IDT))

Notes

1. ↑ ^{1.0 1.1 1.2} 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), Job 076723-32427, file Image:1ucu-3a5x-yale-morph.pdb.gz.
5. ↑ Linear interpolation morph, file Image:1ucu 3a5x linmorph.pdb.gz. See Morphs.

See Also