THE MYCOBACTERIUM-LEPRAE GENOME - SYSTEMATIC SEQUENCE-ANALYSIS IDENTIFIES KEY CATABOLIC ENZYMES, ATP-DEPENDENT TRANSPORT-SYSTEMS AND A NOVEL POLA LOCUS ASSOCIATED WITH GENOMIC VARIABILITY

In the framework of the mycobacterial genome sequencing project, a con tinuous 37 049 bp sequence from the Mycobacterium leprae chromosome ha s been determined, Computer analysis revealed 10 complete open reading frames, and nine of their products show similarity to known proteins, Seven of these were identified as the enzyme isocitrate lyase, two P- type ATPase cation transporters, two AMP-binding proteins, the ribosom al protein S1, and DNA polymerase I, Interestingly, the polA gene, enc oding DNA polymerase, is flanked by two inverted copies of a new class of the M. leprae specific repetitive sequence, RLEP, and this structu re resembles a transposable element, A second copy of this element was found at another locus in the genome, but the two copies were not pre sent in equal amounts and could not be found in all isolates of M. lep rae, This is the first evidence for genomic variability in the leprosy bacillus and might ultimately be useful for developing a molecular te st capable of distinguishing between strains of M. leprae.