The inter- and intramol. interactions between the different domains of the catalase-peroxidase KatG from Mycobacterium tuberculosis were analyzed using the two-hybrid assay. It was shown that the dimerization of the enzyme is due to a strong interaction of the first 99 amino acids of the N-terminal domain whereas the C-terminal domain does not play a role in the dimerization. In addn., an intramol. interaction between the N- and C-terminal domains was detected which might play a functional role in the mechanism of the enzyme. [on SciFinder (R)]