The flavoenzyme ferredoxin-NADP+ reductase (FNR) catalyzes the production of NADPH during photosynthesis. Whereas the structures of FNRs from spinach leaf and a cyanobacterium as well as many of their homologs have been solved, none of these studies has yielded a productive geometry of the flavin-nicotinamide interaction. Here, we show that this failure occurs because nicotinamide binding to wild type FNR involves the energetically unfavorable displacement of the C-terminal Tyr side chain. We used mutants of this residue (Tyr 308) of pea FNR to obtain the structures of productive NADP+ and NADPH complexes. These structures reveal a unique NADP+ binding mode in which the nicotinamide ring is not parallel to the flavin isoalloxazine ring, but lies against it at an angle of approximately 30 degrees, with the C4 atom 3 A from the flavin N5 atom.
A productive NADP+ binding mode of ferredoxin-NADP+ reductase revealed by protein engineering and crystallographic studies / Z. Deng, A. Aliverti, G. Zanetti, A.K. Arakaki, J. Ottado, E.G. Orellano, N.B. Calcaterra, E.A. Ceccarelli, N. Carrillo, P.A. Karplus. - In: NATURE STRUCTURAL BIOLOGY. - ISSN 1072-8368. - 6:9(1999 Sep), pp. 847-853.
|Titolo:||A productive NADP+ binding mode of ferredoxin-NADP+ reductase revealed by protein engineering and crystallographic studies|
ALIVERTI, ALESSANDRO (Secondo)
|Parole Chiave:||photosynthesis ; protein ; enzyme ; hydride transfer ; biological oxidoreduction ; charge-transfer complex ; protein engineering ; flavin nucleotide ; nicotinamide dinucleotide|
|Settore Scientifico Disciplinare:||Settore BIO/10 - Biochimica|
Settore BIO/11 - Biologia Molecolare
Settore BIO/04 - Fisiologia Vegetale
|Data di pubblicazione:||set-1999|
|Digital Object Identifier (DOI):||http://dx.doi.org/10.1038/12307|
|Appare nelle tipologie:||01 - Articolo su periodico|