[Mutational analysis of the CytR protein binding site within the regulatory region of Escherichia coli udp gene].
Site-specific mutagenesis of the pentameric motif TGCAA within the regulatory region of the udp gene with coordinates -68 and -64 relative to the transcription initiation site was performed. Nine mutant promoters containing multiple nucleotide base-pair substitutions in this pentameric motif were isolated and characterized. One mutant contained a deletion of the C/G nucleotide pair in the -66 position. Isolated mutant promoters were cloned into a low-copy-number expression vector pJEL250 to determine the level of their expression, depending on the allelic state of cytR and cya genes. The level of CytR-dependent regulation of the udp gene and the ability to titrate the CytR repressor in vivo were shown to be drastically decreased in all mutant promoters isolated. On the basis of these results, it is concluded that the pentameric motif TGCAA plays a key role in binding the CytR repressor protein to the udp gene promoter.
Domakova
E V
EV
State Research Institute of Genetics and Selection of Industrial Microorganisms, Moscow.
Erraĭs
L L
LL
Eremina
S Iu
SIu
Mironova
A S
AS
D001665:Binding Sites / Q000235:genetics; D004252:DNA Mutational Analysis; D004269:DNA, Bacterial / Q000235:genetics*; D004926:Escherichia coli / Q000235:genetics*; D029968:Escherichia coli Proteins; D015964:Gene Expression Regulation, Bacterial; D005798:Genes, Bacterial; D011401:Promoter Regions, Genetic / Q000235:genetics; D011485:Protein Binding; D012097:Repressor Proteins / Q000235:genetics*; D015533:Transcriptional Activation
C048425:CytR protein, E coli; D004269:DNA, Bacterial; D029968:Escherichia coli Proteins; D012097:Repressor Proteins