The cloning and expression of the aroL gene from Escherichia coli K12. Purification and complete amino acid sequence of shikimate kinase II, the aroL-gene product

Abstract

The aroL gene encoding the enzyme shikimate kinase II was cloned from Escherichia coli K12. Construction of over-expressing strains permitted for the first time the purification to homogeneity of a monofunctional shikimate kinase. The complete amino acid sequence of shikimate kinase II was determined by a combined nucleotide and direct amino acid sequencing strategy. E. coli shikimate kinase II is a monomeric enzyme containing 173 amino acid residues with a calculated Mr 18,937. The amino acid sequence contains a region homologous with other kinases and ATP-requiring enzymes. Evidence is presented suggesting that the transcriptional start site of the aroL gene is located within a potential operator site.