Amino acids responsible for flagellar shape are distributed in terminal regions of flagellin.
The shape of the flagellar filaments of the bacterium Salmonella typhimurium under ordinary conditions is a left-handed helix. In addition to the normal wild-type filament, non-helical (i.e. straight), right-handed helical (early), or circular (semi-coiled and coiled) filaments and filament with small amplitude (fl-type) have been found in mutants or in filaments reconstituted in vitro. We analysed wild-type flagellin and flagellins from 17 flagellar-shape mutants (6 with straight filaments, 6 with curly filaments, 4 with coiled filaments and 1 with fl-type filament) by amino acid sequencing to identify the mutational sites. All mutant flagellins except that of the fl-type filament had single mutations; the fl-type flagellin had two mutations in the molecule. The sites of these mutations were localized in alpha-helical segments of the terminal regions of flagellin. A possible mechanism of the polymorphism of the flagellar filament is discussed.
Kanto
S
S
ERATO, Research Development Corporation of Japan, Ibaraki.
Okino
H
H
Aizawa
S
S
Yamaguchi
S
S
D000595:Amino Acid Sequence; D002851:Chromatography, High Pressure Liquid; D003488:Cyanogen Bromide; D005407:Flagella / Q000648:ultrastructure*; D005408:Flagellin / Q000235:genetics* / Q000302:isolation & purification / Q000648:ultrastructure; D008969:Molecular Sequence Data; D010446:Peptide Fragments / Q000302:isolation & purification; D010449:Peptide Mapping; D011487:Protein Conformation; D012486:Salmonella typhimurium / Q000235:genetics* / Q000648:ultrastructure; D014357:Trypsin
D010446:Peptide Fragments; D005408:Flagellin; D014357:Trypsin; D003488:Cyanogen Bromide