CLONING AND CHARACTERIZATION OF THE AROA GENE FROM MYCOBACTERIUM-TUBERCULOSIS

The aroA gene from Mycobacterium tuberculosis has been cloned by complementation of an aroA mutant of Escherichia coli after lysogenization with a recombinant DNA library in the λgt11 vector. Detailed characterization of the M. tuberculosis aroA gene by nucleotide sequencing and by immunochemical analysis of the expressed product indicates that it encodes a 5-enolpyruvylshikimate-3-phosphate synthase that is structurally related to analogous enzymes from other bacterial, fungal, and plant sources. The potential use of the cloned genes in construction of genetically defined mutant strains of M. tuberculosis by gene replacement is proposed as a novel approach to the rational attenuation of mycobacterial pathogens and the possible development of new antimycobacterial vaccines.