| Literature DB >> 10467097 |
Z Deng1, A Aliverti, G Zanetti, A K Arakaki, J Ottado, E G Orellano, N B Calcaterra, E A Ceccarelli, N Carrillo, P A Karplus.
Abstract
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.Entities:
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Year: 1999 PMID： 10467097 DOI： 10.1038/12307
Source DB: PubMed Journal: Nat Struct Biol ISSN： 1072-8368