Mutagenesis and regulation of the cysJ promoter of Escherichia coli K-12.
The cysJ promoter of Escherichia coli K-12, which is positively controlled by the CysB regulatory protein, was localized through the formation of a fusion of cysJ, the gene encoding NADPH-cytochrome c reductase with lacZ. The position of the transcription start point was determined and the orientation of transcription was shown to be counterclockwise on the E. coli K-12 map. Oligodeoxyribonucleotide-directed mutagenesis of the inferred -10 and -35 regions indicated that both sites could be altered to produce promoter 'down' mutations. When the -10 region was made to agree with the -10 consensus sequence, there was increased function under conditions of repression (that is, in the presence of cysteine). Upstream deletions, as well as mutations in a region proposed to be involved in binding of the CysB regulatory protein, identified sequences important for promoter activity from -90 to -78 and from -71 to -66. By comparison of the sequences of four cys promoters, a possible CysB-binding site was found which included the region shown to be required for the positive regulation of the cysJ promoter.[1]References
- Mutagenesis and regulation of the cysJ promoter of Escherichia coli K-12. Loudon, J.A., Loughlin, R.E. Gene (1992) [Pubmed]
Annotations and hyperlinks in this abstract are from individual authors of WikiGenes or automatically generated by the WikiGenes Data Mining Engine. The abstract is from MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.About WikiGenesOpen Access LicencePrivacy PolicyTerms of Useapsburg