1ogi
FERREDOXIN:NADP+ REDUCTASE MUTANT WITH THR 155 REPLACED BY GLY AND ALA 160 REPLACED BY THR (T155G-A160T)
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OverviewOverview
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.
About this StructureAbout this Structure
1OGI is a Single protein structure of sequence from Nostoc sp. pcc 7119 with SO4 and FAD as ligands. Active as Ferredoxin--NADP(+) reductase, with EC number 1.18.1.2 Structure known Active Site: AC1. Full crystallographic information is available from OCA.
ReferenceReference
Involvement of the pyrophosphate and the 2'-phosphate binding regions of ferredoxin-NADP+ reductase in coenzyme specificity., Tejero J, Martinez-Julvez M, Mayoral T, Luquita A, Sanz-Aparicio J, Hermoso JA, Hurley JK, Tollin G, Gomez-Moreno C, Medina M, J Biol Chem. 2003 Dec 5;278(49):49203-14. Epub 2003 Sep 18. PMID:14500716
Page seeded by OCA on Mon Nov 5 15:03:48 2007