Cloning and the nucleotide sequence of the genes for Escherichia coli ribosomal proteins L28 (rpmB) and L33 (rmpG)

Abstract

The specialized transducing bacteriophage λdpyrE DNA was used as a source of DNA to clone two ribosomal protein genes rpmB (L28) and rpmG (L33) on the cloning vehicle pACYC184. Using one of these plasmids, the nucleotide sequence of these two genes and their flanking regions were determined. The amino acid sequences of both proteins deduced from the nucleotide sequences match with the amino acid sequences previously determined, with one exception. The nucleotide sequences suggest that these two ribosomal protein genes are cotranstribed. There was no expression of the second gene of the operon, rpmG, in the absence of the 5′ sequences adjacent to the first gene, rmpB. Observation of the structure of mRNA also strongly supports the idea that rpmB and rpmG are in a single transcription unit whose order is: rpmBp-rpmB-rpmG-rpmGt.