ABSTRACT
Escherichia coli 397c is temperature sensitive for growth at 43.5 degrees C and unable to plate bacteriophage P2 at 33 degrees C. The mutation conferring these phenotypes was mapped to the rpoC gene. RNA synthesis is temperature sensitive in the mutant strain, and the beta' subunit of RNA polymerase isolated from this strain exhibits increased electrophoretic mobility. DNA sequence analysis revealed that the mutation is a deletion of 16 bp, resulting in a frameshift that leads to truncation of the beta' subunit at the carboxy terminus.
Subject(s)
Bacteriophage P2/growth & development , DNA-Directed RNA Polymerases/genetics , Escherichia coli/genetics , Frameshift Mutation , Amino Acid Sequence , Base Sequence , DNA-Directed RNA Polymerases/chemistry , DNA-Directed RNA Polymerases/metabolism , Escherichia coli/enzymology , Escherichia coli/virology , Molecular Sequence Data , Phenotype , RNA, Bacterial/biosynthesis , Sequence Deletion , TemperatureABSTRACT
The nucleotide sequence of the rpoD gene (encoding the primary sigma-70 (sigma 70) subunit of RNA polymerase) from Escherichia coli C was determined. This gene differs from that of E. coli K-12 by a 30-bp deletion and five single-bp substitutions, resulting in a sigma 70 subunit with three amino acid (aa) changes and a deletion of ten acidic aa.