Nucleotide sequence and regulated expression of the Salmonella fljA gene encoding a repressor of the phase 1 flagellin gene.
The nucleotide sequence of Salmonella abortus-equi fljA, which together with the phase 2 flagellin gene constitutes the fljBA operon and encodes the repressor for the phase 1 flagellin gene fliC, was determined. The repressor was predicted to be a basic protein consisting of 179 amino acid residues (M(r) = 20419 Da) encoded by ORFII. This was confirmed by the fact that host fliC is repressed by plasmid-encoded ORFII, which indeed expresses a 20 kDa product as determined by urea SDS-polyacrylamide gel electrophoresis. An amino acid sequence capable of forming a helix-turn-helix type of structure was predicted in the C-terminal region of FljA. A rho-independent intercistronic terminator was detected between fljB and fljA. Chloramphenicol acetyltransferase (CAT) assays of fusions indicated that the terminator is capable of reducing expression of fljA to the level of a few percent, relative to fljB in broth cultures and to 1% in M9 glycerol cultures.
Hanafusa
T
T
Department of Biology, Faculty of Science, Okayama University, Japan.
Saito
K
K
Tominaga
A
A
Enomoto
M
M
D000595:Amino Acid Sequence; D001426:Bacterial Proteins / Q000235:genetics*; D001483:Base Sequence; D015500:Chloramphenicol O-Acetyltransferase / Q000235:genetics; D003001:Cloning, Molecular; D005408:Flagellin / Q000096:biosynthesis*; D015964:Gene Expression Regulation, Bacterial; D005798:Genes, Bacterial / Q000235:genetics*; D014644:Genetic Variation; D008969:Molecular Sequence Data; D016366:Open Reading Frames; D009876:Operon; D011993:Recombinant Fusion Proteins / Q000096:biosynthesis; D012097:Repressor Proteins / Q000096:biosynthesis / Q000235:genetics*; D012234:Rho Factor / Q000378:metabolism; D012475:Salmonella / Q000235:genetics*; D017422:Sequence Analysis, DNA; D013728:Terminator Regions, Genetic
D001426:Bacterial Proteins; C079830:FljA protein, Salmonella; D011993:Recombinant Fusion Proteins; D012097:Repressor Proteins; D012234:Rho Factor; D005408:Flagellin; D015500:Chloramphenicol O-Acetyltransferase