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OxyR, a positive regulator of hydrogen peroxide-inducible genes in Escherichia coli and Salmonella typhimurium, is homologous to a family of bacterial regulatory proteins.
- Source :
- Proceedings of the National Academy of Sciences of the United States of America; May 1989, Vol. 86 Issue: 10 p3484-3488, 5p
- Publication Year :
- 1989
-
Abstract
- The oxyR gene is required for the induction of a regulon of hydrogen peroxide-inducible genes in Escherichia coli and Salmonella typhimurium. The E. coli oxyR gene has been cloned and sequenced, revealing an open reading frame (305 amino acids) that encodes a 34.4-kDa protein, which is produced in maxicells carrying the oxyR clone. The OxyR protein shows homology to a family of positive regulatory proteins including LysR in E. coli and NodD in Rhizobium. Like them, oxyR appears to be negatively autoregulated: an oxyR::lacZ gene fusion produced 5-fold higher levels of beta-galactosidase activity in oxyR null mutants compared to oxyR+ controls, and extracts from an OxyR-overproducing strain were able to protect regions (-27 to +21) of the oxyR promoter from DNase I digestion. DNA sequence analysis of the oxyR2 mutation, which causes overexpression of oxyR-regulated proteins in the absence of oxidative stress, showed that the oxyR2 phenotype is due to a missense mutation (C.G to T.A transition) that changes alanine to valine at amino acid position 234 of OxyR.
Details
- Language :
- English
- ISSN :
- 00278424 and 10916490
- Volume :
- 86
- Issue :
- 10
- Database :
- Supplemental Index
- Journal :
- Proceedings of the National Academy of Sciences of the United States of America
- Publication Type :
- Periodical
- Accession number :
- ejs60460802
- Full Text :
- https://doi.org/10.1073/pnas.86.10.3484