Mycocyclosin synthase (CYP121)

CYP121 (Mycocyclosin synthase) is a cytochrome P450 enzyme found in Mycobacterium tuberculosis, encoded by the gene Rv2276. It catalyzes a unique intramolecular C–C cross-linking reaction between the two tyrosyl residues in cyclo(L-Tyr-L-Tyr) (cYY), forming the macrocyclic compound mycocyclosin, which is essential for the viability of M. tuberculosis[1][2][3][4]. Unlike canonical P450 enzymes that mediate oxygen insertion, CYP121 employs a radical-based mechanism for carbon–carbon bond formation and can also catalyze peroxidase-type reactions, including hydroxylation and O-demethylation[2][3][4]. CYP121 is considered a validated and essential drug target for tuberculosis therapy—loss-of-function studies demonstrate it is required for pathogen survival[3]. It belongs to the cytochrome P450 superfamily, and its unique chemistry makes it a model for understanding P450 diversity and a focus for anti-tubercular drug development. No approved drugs specifically target CYP121 yet, but the active site structure and reaction mechanism provide a basis for rational inhibitor design[1][2][3][4].

Other names

Cytochrome P450 121CYP121A1Rv2276

Inhibition leads to blockage of mycocyclosin biosynthesis, essential for M. tuberculosis survival