| Literature DB >> 1502169 |
M P Schmitt1, E M Twiddy, R K Holmes.
Abstract
The diphtheria toxin repressor gene (dtxR) encodes a protein (DtxR) that regulates transcription of the diphtheria toxin gene (tox) by an iron-dependent mechanism. Cloned dtxR was expressed in Escherichia coli from the phage T7 gene 10 promoter, and DtxR was purified. Specific binding of DtxR to the tox+ operator was dependent on reduction of DtxR and the presence of ferrous ions. DtxR protected a sequence of approximately 30 nucleotide pairs, partially overlapping the tox promoter and containing a region of dyad symmetry, from digestion by DNase I. DtxR exhibited very little binding to the mutant tox-201 operator region and failed to bind to the promoter/operator region of the ferric uptake regulation (fur) gene of E. coli.Entities:
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Year: 1992 PMID: 1502169 PMCID: PMC49753 DOI: 10.1073/pnas.89.16.7576
Source DB: PubMed Journal: Proc Natl Acad Sci U S A ISSN: 0027-8424 Impact factor: 11.205