View source for 2bn4

[[Image:2bn4.gif|left|200px]]<br />
<applet load="2bn4" size="450" color="white" frame="true" align="right" spinBox="true" 
caption="2bn4, resolution 2.91&Aring;" />
'''A SECOND FMN-BINDING SITE IN YEAST NADPH-CYTOCHROME P450 REDUCTASE SUGGESTS A NOVEL MECHANISM OF ELECTRON TRANSFER BY DIFLAVIN REDUCTASE'''<br />

==Overview==
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).

==About this Structure==
2BN4 is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Saccharomyces_cerevisiae Saccharomyces cerevisiae] with FAD, FMN and NAP as [http://en.wikipedia.org/wiki/ligands ligands]. Active as [http://en.wikipedia.org/wiki/NADPH--hemoprotein_reductase NADPH--hemoprotein reductase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=1.6.2.4 1.6.2.4] Structure known Active Site: AC1. Full crystallographic information is available from [http://ispc.weizmann.ac.il/oca-bin/ocashort?id=2BN4 OCA]. 

==Reference==
A second FMN binding site in yeast NADPH-cytochrome P450 reductase suggests a mechanism of electron transfer by diflavin reductases., Lamb DC, Kim Y, Yermalitskaya LV, Yermalitsky VN, Lepesheva GI, Kelly SL, Waterman MR, Podust LM, Structure. 2006 Jan;14(1):51-61. PMID:[http://ispc.weizmann.ac.il//pmbin/getpm?pmid=16407065 16407065]
[[Category: NADPH--hemoprotein reductase]]
[[Category: Saccharomyces cerevisiae]]
[[Category: Single protein]]
[[Category: Kelly, S.L.]]
[[Category: Kim, Y.]]
[[Category: Lamb, D.C.]]
[[Category: Lepesheva, G.I.]]
[[Category: Podust, L.M.]]
[[Category: Waterman, M.R.]]
[[Category: Yermalitskaya, L.V.]]
[[Category: Yermalitsky, V.N.]]
[[Category: FAD]]
[[Category: FMN]]
[[Category: NAP]]
[[Category: cpr]]
[[Category: diflavin reductase]]
[[Category: electron transfer]]
[[Category: fad]]
[[Category: flavoprotein]]
[[Category: fmn-binding]]
[[Category: nadph]]
[[Category: oxidoreductase.]]

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