1996年6月21日
Self-assembly of the filament capping protein, FliD, of bacterial flagella into an annular structure
Journal of Molecular Biology
- ,
- ,
- 巻
- 259
- 号
- 4
- 開始ページ
- 679
- 終了ページ
- 686
- 記述言語
- 英語
- 掲載種別
- DOI
- 10.1006/jmbi.1996.0349
- 出版者・発行元
- Academic Press
A bacterial flagellum has a cap structure at the tip of the external filament. The cap is composed of the FliD protein (M(r), 49 x 103), and plays an essential role in the polymerization of the filament protein, flagellin, which is believed to be transported through a central channel in the flagellum. A fliD-deficient mutant becomes non-motile because it lacks flagellar filaments and leaks flagellin monomer out into the medium. We have constructed a FliD-overproducing plasmid and purified the protein. The purified FliD at high concentration formed a large complex (M(r), ca. 600 x 103) under physiological conditions. The complex was found by electron microscopy to be ring shaped. Image analysis revealed that the complex consisted of five substructures arranged in a pentagonal shape. Its outer diameter, approximately 10 nm, was about the same as that of the cap at the tip of the wild-type flagella. When the annular structure was added to the culture medium of a Salmonella fliD mutant, almost all of the cells became able to swim. Overall, about ten molecules of FliD self-assemble into an annular structure in vitro, forming the functional capping structure by incorporating flagellin at the tip of the flagellar filament in vivo.
- ID情報
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- DOI : 10.1006/jmbi.1996.0349
- ISSN : 0022-2836
- PubMed ID : 8683574
- SCOPUS ID : 0030596502