The priB gene encoding the primosomal replication n protein of Escherichia coli.

The gene encoding protein n of the Escherichia coli primosome has been discovered in the rpsF-rpsR-rplI ribosomal protein operon and designated priB. The low copy number of PriB protein and the distinctive codon usage of its gene argue against its being a ribosomal protein. A strain which overproduces PriB was constructed and has been used to purify the protein to homogeneity. The overproduced protein behaves like that purified from wild-type cells.