PMCCPMCCPMCC

Search tips
Search criteria 

Advanced

 
Logo of jbacterPermissionsJournals.ASM.orgJournalJB ArticleJournal InfoAuthorsReviewers
 
J Bacteriol. Aug 1995; 177(15): 4437–4441.
PMCID: PMC177194
CadC, the transcriptional regulatory protein of the cadmium resistance system of Staphylococcus aureus plasmid pI258.
G Endo and S Silver
Department of Microbiology & Immunology, University of Illinois College of Medicine, Chicago 60612-7344, USA.
Abstract
The CadC protein from the cadA cadmium resistance operon of Staphylococcus aureus plasmid pI258 regulates transcription of this system in vitro. The CadC protein was overproduced in Escherichia coli cells and partially purified. Gel shift assays of the proposed cadA operator/promoter region DNA showed specific association with the CadC protein. Control arsenic resistance operator/promoter DNA from the same plasmid was not shifted by the CadC protein. Cd2+, Bi3+, and Pb2+ caused the release of CadC from DNA in gel retardation assays. DNase I footprinting measurements showed that the CadC protein specifically associated with and protected a region of operator/promoter DNA from nucleotide positions -7 to +14 relative to the start point of mRNA synthesis. Runoff transcription assays with the operator/promoter region of DNA (plus the first 69 nucleotides of the cadC gene) and purified E. coli RNA polymerase gave an mRNA product of the predicted size. Added CadC protein inhibited transcription in vitro.
Full Text
The Full Text of this article is available as a PDF (424K).
Articles from Journal of Bacteriology are provided here courtesy of
American Society for Microbiology (ASM)