Cloning, sequencing, and transcriptional analysis of the dnaK heat shock operon of Listeria monocytogenes.
The complete dnaK operon of Listeria monocytogenes was isolated by chromosome walking using the previously cloned dnaK gene as a probe. Molecular analysis of the locus identified 6 genes in the order hrcA, grpE, dnaK, dnaJ, orf35, and orf29. Primer extension analysis revealed 3 transcription start sites-S1, S2, and S3-upstream of the hrcA, grpE, and dnaJ, respectively. The transcription from S1 was heat inducible. Analysis of the sequences revealed the consensus promoter sequences of gram-positive bacteria, P1 and P2 upstream of the hrcA and dnaJ, respectively. The hrcA gene and a regulatory sequence, designated CIRCE (controlling inverted repeat of chaperone expression), play a role in the regulation of expression of the dnaK locus in response to heat shock in several gram-positive bacteria. Their presence upstream of the dnaK locus in L. monocytogenes suggested a similar regulatory mechanism for the transcription initiated at the promoter, P1. Northern blot analysis led to the detection of 4 mRNA species of 4.9 kb, 3.6 kb, 3.6 kb, and 1.2 kb; the first 2 species were heat inducible. The current results indicate that 4 distinct transcripts directed by 3 promoters are involved in the expression of the dnaK operon of L. monocytogenes.
Hanawa
T
T
Department of Microbiology, Kyorin University School of Medicine, Mitaka, Tokyo, Japan.
Kai
M
M
Kamiya
S
S
Yamamoto
T
T
D000595:Amino Acid Sequence; D001419:Bacteria / Q000235:genetics; D001426:Bacterial Proteins / Q000235:genetics*; D003001:Cloning, Molecular; D004268:DNA-Binding Proteins; D029968:Escherichia coli Proteins; D015964:Gene Expression Regulation, Bacterial; D005798:Genes, Bacterial; D050956:HSP40 Heat-Shock Proteins; D018840:HSP70 Heat-Shock Proteins / Q000235:genetics*; D006360:Heat-Shock Proteins / Q000235:genetics; D006358:Hot Temperature; D008089:Listeria monocytogenes / Q000235:genetics*; D008969:Molecular Sequence Data; D008970:Molecular Weight; D009876:Operon; D011401:Promoter Regions, Genetic; D012333:RNA, Messenger / Q000235:genetics; D012045:Regulatory Sequences, Nucleic Acid; D012097:Repressor Proteins / Q000235:genetics; D017421:Sequence Analysis; D013045:Species Specificity; D014158:Transcription, Genetic
D001426:Bacterial Proteins; D004268:DNA-Binding Proteins; C494635:DnaJ protein, E coli; D029968:Escherichia coli Proteins; C068113:GrpE protein, Bacteria; D050956:HSP40 Heat-Shock Proteins; D018840:HSP70 Heat-Shock Proteins; D006360:Heat-Shock Proteins; D012333:RNA, Messenger; D012097:Repressor Proteins; C406264:orf29 protein, Listeria monocytogenes; C104236:orf35 protein, Bacillus subtilis; C063842:dnaK protein, E coli