Linked Life Data

18973834

Source:http://linkedlifedata.com/resource/pubmed/id/18973834

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
2
pubmed:dateCreated
2009-1-12
pubmed:abstractText
Ferredoxin-NADP(H) reductases catalyse the reversible hydride/electron exchange between NADP(H) and ferredoxin/flavodoxin, comprising a structurally defined family of flavoenzymes with two distinct subclasses. Those present in Gram-negative bacteria (FPRs) display turnover numbers of 1-5 s(-1) while the homologues of cyanobacteria and plants (FNRs) developed a 100-fold activity increase. We investigated nucleotide interactions and hydride transfer in Rhodobacter capsulatus FPR comparing them to those reported for FNRs. NADP(H) binding proceeds as in FNRs with stacking of the nicotinamide on the flavin, which resulted in formation of charge-transfer complexes prior to hydride exchange. The affinity of FPR for both NADP(H) and 2'-P-AMP was 100-fold lower than that of FNRs. The crystal structure of FPR in complex with 2'-P-AMP and NADP(+) allowed modelling of the adenosine ring system bound to the protein, whereas the nicotinamide portion was either not visible or protruding toward solvent in different obtained crystals. Stabilising contacts with the active site residues are different in the two reductase classes. We conclude that evolution to higher activities in FNRs was partially favoured by modification of NADP(H) binding in the initial complexes through changes in the active site residues involved in stabilisation of the adenosine portion of the nucleotide and in the mobile C-terminus of FPR.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Feb
pubmed:issn
0006-3002
pubmed:author
pubmed:issnType
Print
pubmed:volume
1794
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
199-210
pubmed:meshHeading
pubmed:year
2009
pubmed:articleTitle
Coenzyme binding and hydride transfer in Rhodobacter capsulatus ferredoxin/flavodoxin NADP(H) oxidoreductase.
pubmed:affiliation
Instituto de Biología Molecular y Celular de Rosario, Universidad Nacional de Rosario, Suipacha 531, S2002LRK Rosario, Argentina.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't