2BSA

Ferredoxin-Nadp Reductase (Mutation: Y 303 S) complexed with NADP

Summary for 2BSA

• Entry DOI: 10.2210/pdb2bsa/pdb
• Related: 1B2R 1BJK 1BQE 1E62 1E63 1E64 1EWY 1GJR 1GO2 1GR1 1H42 1H85 1OGI 1OGJ 1QGY 1QGZ 1QH0 1QUE 1QUF 1W34 1W35 1W87 2BMW
• Descriptor: FERREDOXIN-NADP REDUCTASE, FLAVIN-ADENINE DINUCLEOTIDE, NADP NICOTINAMIDE-ADENINE-DINUCLEOTIDE PHOSPHATE, ... (4 entities in total)
• Functional Keywords: oxidoreductase, fad, flavoprotein, fnr, membrane, nadp, nadp reductase, phycobilisome, thylakoid
• Biological source: ANABAENA SP.
• Cellular location: Cellular thylakoid membrane; Peripheral membrane protein; Cytoplasmic side: P21890
• Total number of polymer chains: 1
• Total formula weight: 35436.50

Authors

Maya, C.M.,Hermoso, J.A.,Perez-Dorado, I.,Tejero, J.,Julvez, M.M.,Gomez-Moreno, C.,Medina, M. (deposition date: 2005-05-20, release date: 2005-10-19, Last modification date: 2023-12-13)

Primary citation

Tejero, J.,Perez-Dorado, I.,Maya, C.M.,Julvez, M.M.,Sanz-Aparicio, J.,Gomez-Moreno, C.,Hermoso, J.A.,Medina, M.
C-Terminal Tyrosine of Ferredoxin-Nadp(+) Reductase in Hydride Transfer Processes with Nad(P)(+)/H.
Biochemistry, 44:13477-, 2005

PubMed Abstract: Ferredoxin-NADP+ reductase (FNR) catalyzes the reduction of NADP+ to NADPH in an overall reversible reaction, showing some differences in the mechanisms between cyanobacterial and higher plant FNRs. During hydride transfer it is proposed that the FNR C-terminal Tyr is displaced by the nicotinamide. Thus, this C-terminal Tyr might be involved not only in modulating the flavin redox properties, as already shown, but also in nicotinamide binding and hydride transfer. FNR variants from the cyanobacterium Anabaena in which the C-terminal Tyr has been replaced by Trp, Phe, or Ser have been produced. All FNR variants show enhanced NADP+ and NAD+ binding, especially Tyr303Ser, which correlates with a noticeable improvement of NADH-dependent reactions. Nevertheless, the Tyr303Ser variant shows a decrease in the steady-state kcat value with NADPH. Fast kinetic analysis of the hydride transfer shows that the low efficiency observed for this mutant FNR under steady-state conditions is not due to a lack of catalytic ability but rather to the strong enzyme-coenzyme interaction. Three-dimensional structures for Tyr303Ser and Tyr303Trp variants and its complexes with NADP+ show significant differences between plant and cyanobacterial FNRs. Our results suggest that modulation of coenzyme affinity is highly influenced by the strength of the C-terminus-FAD interaction and that subtle changes between plant and cyanobacterial structures are able to modify the energy of that interaction. Additionally, it is shown that the C-terminal Tyr of FNR lowers the affinity for NADP+/H to levels compatible with steady-state turnover during the catalytic cycle, but it is not involved in the hydride transfer itself.

PubMed: 16216071
DOI: 10.1021/BI051278C

Experimental method

X-RAY DIFFRACTION (1.92 Å)