Cloning of the fliI gene from Rhodobacter sphaeroides WS8 by analysis of a transposon mutant with impaired motility.
A transposon mutant of Rhodobacter sphaeroides WS8 was isolated that showed reduced swarming on soft agar plates. Liquid cultures of this mutant (M18) showed a low percentage of motile swimming cells in mid-exponential phase and a low level of extracellular flagellin protein by Western blotting. M18 was complemented by a clone from a library of R. sphaeroides WS8 DNA, and restriction mapping of the site of TnphoA insertion in the mutant, coupled with DNA sequencing, showed that it had a defect in the fliI gene. To determine if a partly functional fliI gene was giving the low-motility phenotype of M18, a drug resistance omega cartridge was inserted into the gene to give a complete null mutant. This null strain also produced a low percentage of motile cells. Possible reasons for this apparent fliI-independent flagellar formation are discussed.
Goodfellow
I G
IG
Department of Life Science, Nottingham University, University Park, UK.
Pollitt
C E
CE
Sockett
R E
RE
D000595:Amino Acid Sequence; D001426:Bacterial Proteins; D004251:DNA Transposable Elements; D005407:Flagella / Q000502:physiology; D005798:Genes, Bacterial; D008969:Molecular Sequence Data; D009154:Mutation; D011506:Proteins / Q000235:genetics*; D006180:Proton-Translocating ATPases; D015183:Restriction Mapping; D012242:Rhodobacter sphaeroides / Q000235:genetics* / Q000502:physiology; D012486:Salmonella typhimurium / Q000235:genetics; D017386:Sequence Homology, Amino Acid; D016959:Xanthomonas campestris / Q000235:genetics
D001426:Bacterial Proteins; D004251:DNA Transposable Elements; D011506:Proteins; C069251:fliI protein, bacteria; D006180:Proton-Translocating ATPases