UV cross-linking of the Bacillus subtilis RNA polymerase to DNA in promoter and non-promoter complexes.
Complexes between Bacillus subtilus RNA polymerase and 32P-labeled DNA were irradiated with UV light and digested with nuclease; electrophoresis and autoradiography were used to identify the polymerase subunits cross-linked to DNA. These experiments showed: 1) that cross-linkage of promoter complexes yielded predominantly the beta and sigma subunits; 2) that beta, beta', and sigma were detected in non-promoter complexes; 3) that addition of the delta subunit or high concentrations of NaCl decreased cross-linkage of all subunits, especially the cross-linkage of the sigma subunit in non-promoter complexes and the binding of polymerase at DNA ends; 4) that different patterns of cross-linkage were obtained at 0 degrees C (conditions favoring the formation of closed complexes) and 37 degrees C (conditions favoring the formation of open complexes); and 5) predominantly beta and possibly alpha were cross-linked by irradiation of core-DNA complexes whereas similar experiments with core-delta complexed to DNA showed the efficient cross-linkage of beta' and beta.
D001412:Bacillus subtilis / Q000201:enzymology*; D001435:Bacteriophages / Q000235:genetics; D004279:DNA, Viral / Q000378:metabolism* / Q000528:radiation effects; D012321:DNA-Directed RNA Polymerases / Q000378:metabolism* / Q000528:radiation effects; D009876:Operon; D010957:Plasmids; D012965:Sodium Chloride / Q000494:pharmacology; D013696:Temperature; D014466:Ultraviolet Rays
D004279:DNA, Viral; D012965:Sodium Chloride; D012321:DNA-Directed RNA Polymerases