Molecular characterization of the CmbR activator-binding site in the metC-cysK promoter region in Lactococcus lactis.
The metC-cysK operon involved in sulphur metabolism in Lactococcus lactis is positively regulated by the LysR-type protein CmbR. Transcription from the metC promoter is activated when concentrations of methionine and cysteine in the growth medium are low. The metC promoter region contains two direct and three inverted repeats. Deletion analysis indicated that direct repeat 2 (DR2) is required for activation of the metC promoter by CmbR. Gel mobility shift assays confirmed that CmbR binds to a 407 bp DNA fragment containing the metC promoter. This binding was stimulated by O-acetyl-L-serine. Competition experiments with deletion variants of the metC promoter showed that CmbR binding only occurred with fragments containing an intact DR2, confirming that DR2 is the CmbR binding site within the metC promoter.
Golic
Natasa
N
Institute of Molecular Genetics and Genetic Engineering, Belgrade, Yugoslavia.|Flavour, Nutrition and Ingredients Department, NIZO Food Research, PO Box 20, 6710 BA Ede, The Netherlands.|Wageningen Centre for Food Sciences, Wageningen, The Netherlands.
Schliekelmann
Martijn
M
Flavour, Nutrition and Ingredients Department, NIZO Food Research, PO Box 20, 6710 BA Ede, The Netherlands.|Wageningen Centre for Food Sciences, Wageningen, The Netherlands.
Fernández
María
M
Flavour, Nutrition and Ingredients Department, NIZO Food Research, PO Box 20, 6710 BA Ede, The Netherlands.|Wageningen Centre for Food Sciences, Wageningen, The Netherlands.
Kleerebezem
Michiel
M
Flavour, Nutrition and Ingredients Department, NIZO Food Research, PO Box 20, 6710 BA Ede, The Netherlands.|Wageningen Centre for Food Sciences, Wageningen, The Netherlands.
van Kranenburg
Richard
R
Flavour, Nutrition and Ingredients Department, NIZO Food Research, PO Box 20, 6710 BA Ede, The Netherlands.|Wageningen Centre for Food Sciences, Wageningen, The Netherlands.
D001426:Bacterial Proteins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D001483:Base Sequence; D001665:Binding Sites; D003545:Cysteine / Q000378:metabolism; D017353:Gene Deletion; D015964:Gene Expression Regulation, Bacterial; D013294:Lactococcus lactis / Q000235:genetics / Q000254:growth & development / Q000378:metabolism*; D008715:Methionine / Q000378:metabolism; D008969:Molecular Sequence Data; D011401:Promoter Regions, Genetic; D012091:Repetitive Sequences, Nucleic Acid / Q000235:genetics*; D014157:Transcription Factors / Q000378:metabolism*; D014158:Transcription, Genetic
D001426:Bacterial Proteins; C443981:CmbR protein, Lactococcus lactis; D014157:Transcription Factors; D008715:Methionine; D003545:Cysteine