2BF4

A second FMN-binding site in yeast NADPH-cytochrome P450 reductase suggests a novel mechanism of electron transfer by diflavin reductases.

Summary for 2BF4

• Entry DOI: 10.2210/pdb2bf4/pdb
• Descriptor: NADPH-CYTOCHROME P450 REDUCTASE, FLAVIN-ADENINE DINUCLEOTIDE, FLAVIN MONONUCLEOTIDE, ... (6 entities in total)
• Functional Keywords: reductase, nadph-cytochrome p450 reductase, cpr, diflavin reductase, fad, fmn, nadp, electron transfer
• Biological source: SACCHAROMYCES CEREVISIAE (BAKER'S YEAST)
• Total number of polymer chains: 2
• Total formula weight: 156857.57

Authors

Podust, L.M.,Lepesheva, G.I.,Kim, Y.,Yermalitskaya, L.V.,Yermalitsky, V.N.,Lamb, D.C.,Kelly, S.L.,Waterman, M.R. (deposition date: 2004-12-03, release date: 2006-01-17, Last modification date: 2024-05-08)

Primary citation

Lamb, D.C.,Kim, Y.,Yermalitskaya, L.V.,Yermalitsky, V.N.,Lepesheva, G.I.,Kelly, S.L.,Waterman, M.R.,Podust, L.M.
A Second Fmn-Binding Site in Yeast Nadph-Cytochrome P450 Reductase Suggests a Mechanism of Electron Transfer by Diflavin Reductases.
Structure, 14:51-, 2006

PubMed Abstract: NADPH-cytochrome P450 reductase transfers two reducing equivalents derived from a hydride ion of NADPH via FAD and FMN to the large family of microsomal cytochrome P450 monooxygenases in one-electron transfer steps. The mechanism of electron transfer by diflavin reductases remains elusive and controversial. Here, we determined the crystal structure of truncated yeast NADPH-cytochrome P450 reductase, which is functionally active toward its physiological substrate cytochrome P450, and discovered a second FMN binding site at the interface of the connecting and FMN binding domains. The two FMN binding sites have different accessibilities to the bulk solvent and different amino acid environments, suggesting stabilization of different electronic structures of the reduced flavin. Since only one FMN cofactor is required for function, a hypothetical mechanism of electron transfer is discussed that proposes shuttling of a single FMN between these two sites coupled with the transition between two semiquinone forms, neutral (blue) and anionic (red).

PubMed: 16407065
DOI: 10.1016/J.STR.2005.09.015

Experimental method

X-RAY DIFFRACTION (3 Å)