Download MendeleyCrystallographic trapping in the rebeccamycin biosynthetic enzyme RebC
Ryan, K.S., Howard-Jones, A.R., Hamill, M.J., Elliott, S.J., Walsh, C.T., Drennan, C.L.(2007) Proc Natl Acad Sci U S A 104: 15311-15316
- PubMed: 17873060
- DOI: https://doi.org/10.1073/pnas.0707190104
- Primary Citation of Related Structures:
2R0C, 2R0G, 2R0P - PubMed Abstract:
The biosynthesis of rebeccamycin, an antitumor compound, involves the remarkable eight-electron oxidation of chlorinated chromopyrrolic acid. Although one rebeccamycin biosynthetic enzyme is capable of generating low levels of the eight-electron oxidation product on its own, a second protein, RebC, is required to accelerate product formation and eliminate side reactions. However, the mode of action of RebC was largely unknown. Using crystallography, we have determined a likely function for RebC as a flavin hydroxylase, captured two snapshots of its dynamic catalytic cycle, and trapped a reactive molecule, a putative substrate, in its binding pocket. These studies strongly suggest that the role of RebC is to sequester a reactive intermediate produced by its partner protein and to react with it enzymatically, preventing its conversion to a suite of degradation products that includes, at low levels, the desired product.
Organizational Affiliation:
Department of Biology, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, MA 02139, USA.
