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PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
49
pubmed:dateCreated
2003-12-3
pubmed:abstractText
Previous studies indicated that the determinants of coenzyme specificity in ferredoxin-NADP+ reductase (FNR) from Anabaena are situated in the 2'-phosphate (2'-P) NADP+ binding region, and also suggested that other regions must undergo structural rearrangements of the protein backbone during coenzyme binding. Among the residues involved in such specificity could be those located in regions where interaction with the pyrophosphate group of the coenzyme takes place, namely loops 155-160 and 261-268 in Anabaena FNR. In order to learn more about the coenzyme specificity determinants, and to better define the structural basis of coenzyme binding, mutations in the pyrophosphate and 2'-P binding regions of FNR have been introduced. Modification of the pyrophosphate binding region, involving residues Thr-155, Ala-160, and Leu-263, indicates that this region is involved in determining coenzyme specificity and that selected alterations of these positions produce FNR enzymes that are able to bind NAD+. Thus, our results suggest that slightly different structural rearrangements of the backbone chain in the pyrophosphate binding region might determine FNR specificity for the coenzyme. Combined mutations at the 2'-P binding region, involving residues Ser-223, Arg-224, Arg-233, and Tyr-235, in combination with the residues mentioned above in the pyrophosphate binding region have also been carried out in an attempt to increase the FNR affinity for NAD+/H. However, in most cases the analyzed mutants lost the ability for NADP+/H binding and electron transfer, and no major improvements were observed with regard to the efficiency of the reactions with NAD+/H. Therefore, our results confirm that determinants for coenzyme specificity in FNR are also situated in the pyrophosphate binding region and not only in the 2'-P binding region. Such observations also suggest that other regions of the protein, yet to be identified, might also be involved in this process.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Dec
pubmed:issn
0021-9258
pubmed:author
pubmed:issnType
Print
pubmed:day
5
pubmed:volume
278
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
49203-14
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed:year
2003
pubmed:articleTitle
Involvement of the pyrophosphate and the 2'-phosphate binding regions of ferredoxin-NADP+ reductase in coenzyme specificity.
pubmed:affiliation
Departamento de Bioquímica y Biología Molecular y Celular, Facultad de Ciencias, Universidad de Zaragoza, 50009 Zaragoza, Madrid, Spain.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S., Research Support, Non-U.S. Gov't