In vivo cloning of a carboxy-terminal rpoB allele which confers altered transcriptional properties.

A 3'-terminal mutation of the gene encoding the beta subunit of Escherichia coli RNA polymerase was isolated using an in vivo polA(Ts) technique. Cloning of the allele was monitored by virtue of the fact that the deletion delta(rpoB)1570-1 resulted in an altered-size restriction fragment. DNA sequencing confirmed the predicted nature and location of the mutation: delta(rpoB)1570-1 involved an in-frame deletion of 186 bp (62 codons) encoding amino acid residues 967-1028. The phenotype conferred by delta(rpoB)1570-1 is discussed with respect to conserved domains within the beta polypeptide.