Oxidoreductases;
Acting on single donors with incorporation of molecular oxygen (oxygenases);
With incorporation of one atom of oxygen (internal monooxygenases or internal mixed-function oxidases)
The conversion of dichlorochromopyrrolate to dichloroarcyriaflavin A is a complex process that involves two enzyme components. RebP is an NAD-dependent cytochrome P-450 oxygenase that performs an aryl-aryl bond formation yielding the six-ring indolocarbazole scaffold [1]. Along with RebC, a flavin-dependent hydroxylase, it also catalyses the oxidative decarboxylation of both carboxyl groups. The presence of RebC ensures that the only product is the rebeccamycin aglycone dichloroarcyriaflavin A [2]. The enzymes are similar, but not identical, to StaP and StaC, which are involved in the synthesis of staurosporine [3].