Reaction: dichlorochromopyrrolate + 4 O2 + 4 NADH + 4 H+ = dichloroarcyriaflavin A + 2 CO2 + 6 H2O + 4 NAD+
For diagram of reaction click here
Glossary: dichloro-arcyriaflavin A = rebeccamycin aglycone
Systematic name: dichlorochromopyrrolate,NADH:oxygen 2,5-oxidoreductase (dichloroarcyriaflavin A-forming)
Comments: The conversion of dichlorochromopyrrolate to dichloroarcyriaflavin A is a complex process that involves two enzyme components. RebP is an NAD-dependent cytochrome P450 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].
Links to other databases: BRENDA, EXPASY, KEGG, Metacyc, CAS registry number:
References:
1. Makino, M., Sugimoto, H., Shiro, Y., Asamizu, S., Onaka, H. and Nagano, S. Crystal structures and catalytic mechanism of cytochrome P450 StaP that produces the indolocarbazole skeleton. Proc. Natl. Acad. Sci. USA 104:1159 (2007). [PMID: 17606921]
2. Howard-Jones, A.R. and Walsh, C.T. Staurosporine and rebeccamycin aglycones are assembled by the oxidative action of StaP, StaC, and RebC on chromopyrrolic acid. J. Am. Chem. Soc. 128:1228 (2006). [PMID: 16967980]
3. Sanchez, C., Zhu, L., Brana, A.F., Salas, A.P., Rohr, J., Mendez, C. and Salas, J.A. Combinatorial biosynthesis of antitumor indolocarbazole compounds. Proc. Natl. Acad. Sci. USA 102:461 (2005). [PMID: 15625109]