LIPID-SYNTHESIS IN MYCOBACTERIA - CHARACTERIZATION OF THE BIOTIN CARBOXYL CARRIER PROTEIN GENES FROM MYCOBACTERIUM-LEPRAE AND MYCOBACTERIUM-TUBERCULOSIS

The causative agents of leprosy and tuberculosis, Mycobacterium leprae and Mycobacterium tuberculosis, have a lipid-rich cell envelope which contributes to virulence and antibiotic resistance. Acyl coenzyme A c arboxylase, which catalyzes the first committed step of lipid biosynth esis, consists in mycobacteria of two subunits, one of which is biotin ylated. Genes from M. leprae and M. tuberculosis encoding a biotinylat ed protein have been cloned and sequenced. Analysis of the derived pro tein sequences demonstrated the presence of biotin-binding sites and p utative ATP-bicarbonate interaction sites, consistent with the protein s having a biotin carboxylase function as well as with their being bio tin carrier proteins.