An amber mutation in the gene encoding the beta' subunit of Escherichia coli RNA polymerase.
An Escherichia coli strain carrying an amber mutation (UAG) in rpoC, the gene encoding the beta prime subunit of RNA polymerase, was isolated after mutagenesis with nitrosoguanidine. The mutation was moved into an unmutagenized strain carrying the supD43,74 allele, which encodes a temperature-sensitive su1 amber suppressor, and sue alleles, which enhance the efficiency of the suppressor. In this background, beta prime is not synthesized at high temperature. Suppression of the mutation by the non-temperature-sensitive amber suppressor su1+ yields a protein which is functional at all temperatures examined (30, 37, and 42 degrees C).
D004262:DNA Restriction Enzymes; D012321:DNA-Directed RNA Polymerases / Q000235:genetics*; D004926:Escherichia coli / Q000201:enzymology / Q000235:genetics*; D005796:Genes; D005798:Genes, Bacterial; D005838:Genotype; D046911:Macromolecular Substances; D009154:Mutation; D010957:Plasmids; D013045:Species Specificity
D046911:Macromolecular Substances; D012321:DNA-Directed RNA Polymerases; D004262:DNA Restriction Enzymes