title: Potassium permanganate susceptibility of sigma E-RNA polymerase-promoter complexes.
abstract: We used potassium permanganate (KMnO4) to identify unpaired thymidine (T) residues in promoter complexes formed by RNA polymerase (RNAP) associated with sigma E (sigma E-RNAP) from Bacillus subtilis. We found that a region of the spoIIID promoter from at least -10 to +1 becomes melted in the presence of this polymerase. In promoter complexes formed by RNAP associated with a mutant sigma E that melts promoter DNA inefficiently, we noted additional KMnO4 sensitivity at the -11 position of the spoIIID promoter. We suggest that the base pair at -11 is unpaired in both mutant and wild type (wt) complexes; however, close proximity of wt sigma E-RNAP with the T at -11 may protect it from KMnO4 attack. The absence of a close contact between the mutant sigma E-RNAP and the base at -11 may explain why this polymerase uses promoters less efficiently than wt sigma E-RNAP.
authors.affiliation: Department of Microbiology and Immunology, Emory University School of Medicine, Atlanta GA 30322, USA.
authors.forename: R W
authors.initials: RW
authors.lastname: Seyler
authors.forename: C P
authors.initials: CP
authors.lastname: Moran
mesh_terms: D001412:Bacillus subtilis / Q000187:drug effects / Q000235:genetics; D012321:DNA-Directed RNA Polymerases / Q000187:drug effects* / Q000378:metabolism; D011196:Potassium Permanganate / Q000494:pharmacology*; D011401:Promoter Regions, Genetic / Q000187:drug effects*; D012808:Sigma Factor / Q000187:drug effects* / Q000378:metabolism; D013936:Thymidine / Q000378:metabolism; D014157:Transcription Factors / Q000187:drug effects* / Q000378:metabolism; D014158:Transcription, Genetic
chemical_list: D012808:Sigma Factor; D014157:Transcription Factors; C063202:sporulation-specific sigma factors; D011196:Potassium Permanganate; D012321:DNA-Directed RNA Polymerases; D013936:Thymidine