RRC ID 67787
Author Iizumi T, Nakamura K.
Title Cloning, nucleotide sequence, and regulatory analysis of the Nitrosomonas europaea dnaK gene.
Journal Appl Environ Microbiol
Abstract The dnaK gene of an ammonia-oxidizing bacterium, Nitrosomonas europaea, was cloned and sequenced. It was found that the dnaK gene product was highly homologous to previously analyzed dnaK gene products from other organisms at the amino acid level. Two partial open reading frames located upstream and downstream of the dnaK gene were also found and identified as grpE and dnaJ genes, respectively, by the predicted amino acid homology of their gene products to other bacterial GrpE and DnaJ proteins. Transcription of the dnaK gene was strongly induced by a heat shock from 30 to 37 degrees C. An analysis of the expression of the dnaK gene fused to the lacZ translational reporter gene also showed eightfold increase in beta-galactosidase activity after the heat shock induction. Heat-inducible transcription start sites of the dnaK gene, revealed by primer extension analysis, were located 16 and 17 nucleotides upstream from the translational start codon of the dnaK gene, and the predicted promoter sequence showed a homology to the consensus sequence of sigma 32-dependent heat shock promoters of gram-negative bacteria. The upstream region of the dnaK gene did not contain the inverted repeat structure that was involved in the regulation of the heat shock gene of several gram-negative and gram-positive bacteria. Therefore, we conclude that the heat shock regulatory mechanism of the N. europaea dnaK gene may be similar to the sigma 32-dependent mechanism observed in other gram-negative bacteria.
Volume 63(5)
Pages 1777-84
Published 1997-5-1
DOI 10.1128/aem.63.5.1777-1784.1997
PMID 9143112
PMC PMC168472
MeSH Amino Acid Sequence Bacterial Proteins / genetics Base Sequence Blotting, Northern Blotting, Southern Cloning, Molecular* Codon, Initiator Escherichia coli Proteins* Gene Expression Regulation, Bacterial* Genes, Reporter Gram-Negative Bacteria / genetics HSP40 Heat-Shock Proteins HSP70 Heat-Shock Proteins / genetics* Heat-Shock Proteins / genetics Heat-Shock Proteins / physiology Heat-Shock Response / genetics Lac Operon Molecular Sequence Data Nitrosomonas / genetics* Open Reading Frames Plasmids Promoter Regions, Genetic Recombination, Genetic Repetitive Sequences, Nucleic Acid Restriction Mapping Sequence Homology, Amino Acid Sigma Factor / genetics Sigma Factor / physiology Transcription Factors* Transcription, Genetic beta-Galactosidase / metabolism
IF 4.016
DNA material pHLUX20 (RDB18951)