The enzyme, found in mycobacteria, is involved in the synthesis of beta-D-mannosyl phosphomycoketides. It is a very large polyketide synthase that contains two complete sets of FAS-like fatty acid synthase modules. It binds an acyl-CoA with 5-9 carbons as a starter unit, and extends it by five rounds of alternative additions of malonyl-CoA and methylmalonyl-CoA extender units. Depending on the starter unit, the enzyme forms mycoketide-CoAs of different lengths.
