Open AccessDNA supercolling and aerobic regulation of transcription from theKlebsiella pneumoniae nifLApromoter
Author(s) -
Ray Dixon,
N. Henderson,
Sara Austin
Publication year - 1988
Publication title -
nucleic acids research
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 9.008
H-Index - 537
eISSN - 1362-4954
pISSN - 0305-1048
DOI - 10.1093/nar/16.21.9933
Subject(s) - dna supercoil , biology , dna gyrase , transcription (linguistics) , dna , klebsiella pneumoniae , promoter , topoisomerase , microbiology and biotechnology , gene , gene expression , genetics , escherichia coli , dna replication , linguistics , philosophy
Expression from the K. pneumoniae nifLA promoter is oxygen sensitive and is also inhibited by the DNA gyrase inhibitor coumermycin A1 under anaerobic growth conditions. The activity of this promoter was found to be highly sensitive to changes in DNA topology in vitro. Transcription was completely dependent on negative supercoiling at physiological salt concentrations although transcription from linear or fully relaxed closed circular templates was detectable at KCl concentrations lower than 50 mM. These observations suggest that aerobic regulation of nif transcription may be mediated through the level of DNA supercoiling.