cis-Acting elements responsible for low-temperature-inducible expression of the gene coding for the thermolabile isocitrate dehydrogenase isozyme of a psychrophilic bacterium, Vibrio sp. strain ABE-1.
Transcriptional control of the low-temperature-inducible icdII gene, encoding the thermolabile isocitrate dehydrogenase of a psychrophilic bacterium, Vibrio sp. strain ABE-1, was found to be mediated in part by a transcriptional silencer locating at nucleotide positions -560 to -526 upstream from the transcription start site of icdII. Deletion of the silencer resulted in a 20-fold-increased level of expression of the gene at low temperature (15 degrees C) but not at high temperature (37 degrees C). In addition, a CCAAT sequence located 2 bases upstream of the -35 region was found to be essential for the low-temperature-inducible expression of the gene. By deletion of this sequence, low-temperature-dependent expression of the gene was completely abolished. The ability of the icdII promoter to control the expression of other genes was confirmed by using a fusion gene containing the icdII promoter region and the promoterless icdI open reading frame, which encodes the non-cold-inducible isocitrate dehydrogenase isozyme of Vibrio sp. strain ABE-1. Escherichia coli transformants harboring icdII acquired an ability to grow rapidly at low temperature.
Sahara
T
T
Division of Biological Sciences, Graduate School of Science, Hokkaido University, Sapporo 060-0810, Japan.
Suzuki
M
M
Tsuruha
J
J
Takada
Y
Y
Fukunaga
N
N
D000220:Adaptation, Biological; D003080:Cold Temperature; D004790:Enzyme Induction; D004795:Enzyme Stability; D004926:Escherichia coli / Q000235:genetics; D005798:Genes, Bacterial; D006358:Hot Temperature; D007521:Isocitrate Dehydrogenase / Q000096:biosynthesis / Q000235:genetics*; D007527:Isoenzymes / Q000235:genetics; D012045:Regulatory Sequences, Nucleic Acid; D014170:Transformation, Genetic; D014733:Vibrio / Q000201:enzymology / Q000235:genetics*
D007527:Isoenzymes; D007521:Isocitrate Dehydrogenase