Nucleotide sequence of the Escherichia coli regulatory gene mprA and construction and characterization of mprA-deficient mutants.
In high copy number, the Escherichia coli mprA gene reduces the synthesis of peptide microcins B17 and C7 (MccB17 and MccC7) and blocks the osmoinduction of the proU operon at the transcriptional level. mprA has been sequenced and shown to encode a polypeptide of 176 amino acids (Mr, 20,563). Insertion and deletion mutant mprA alleles were constructed and then transferred to the chromosome by allelic replacement. In these mutants, expression of two mcb-lacZ fusions was fivefold derepressed, indicating a negative regulatory role of mprA on the mcb operon (MccB17). In contrast, no effect of the MprA- mutations on the expression of mcc operon (MccC7) or on the osmoinduction of proU operon was observed.
del Castillo
I
I
Unidad de Genética Molecular, Hospital Ramón y Cajal, Carretera de Colmenar, Madrid, Spain.
González-Pastor
J E
JE
San Millán
J L
JL
Moreno
F
F
D000483:Alleles; D000595:Amino Acid Sequence; D001430:Bacteriocins / Q000037:antagonists & inhibitors; D001483:Base Sequence; D004926:Escherichia coli / Q000235:genetics*; D005798:Genes, Bacterial; D005809:Genes, Regulator; D008969:Molecular Sequence Data; D009154:Mutation; D009876:Operon; D009994:Osmolar Concentration; D010957:Plasmids; D015183:Restriction Mapping; D014158:Transcription, Genetic
D001430:Bacteriocins; C020411:microcin