Genetic and molecular analysis of aroL, the gene for shikimate kinase II in Escherichia coli K-12.

The gene aroL in Escherichia coli K-12, specifying shikimate kinase II, was contransduced with proC at a frequency of 99%. The gene order is lac proC aroL. A 2.7-kilobase BamHI fragment containing aroL+ was cloned into pBR322. This plasmid conferred highly elevated levels of shikimate kinase synthesis which were subject to repression control by tyrR. The aroL gene was localized within a 730-base-pair region by both subcloning and insertional mutagenesis with Tn1000. A second gene, designated aroM and encoding a protein of molecular weight 26,000, is cotranscribed with aroL. Transcription proceeds in the order aroL aroM in a clockwise direction on the chromosome. The function of aroM remains unknown.