PDBsum entry 1bqe

Oxidoreductase

PDB id: 1bqe

Contents

Protein chain

295 a.a. *

Ligands

SO4

FAD

Waters ×267

* Residue conservation analysis

PDB id:

1bqe

Name:

Oxidoreductase

Title:

Ferredoxin:nadp+ reductase mutant with thr 155 replaced by gly (t155g)

Structure:

Ferredoxin--NADP reductase. Chain: a. Synonym: fnr. Engineered: yes. Mutation: yes

Source:

Nostoc sp.. Organism_taxid: 1168. Strain: pcc 7119. Expressed in: escherichia coli. Expression_system_taxid: 562

Resolution:

2.45Å R-factor: 0.160 R-free: 0.240

Authors:

J.A.Hermoso,T.Mayoral,M.Medina,M.Martinez-Ripoll,M.Martinez-Julvez, J.Sanz-Aparicio,C.Gomez-Moreno

Key ref:

M.Medina et al. (2001). Probing the determinants of coenzyme specificity in ferredoxin-NADP+ reductase by site-directed mutagenesis. J Biol Chem, 276, 11902-11912. PubMed id: 11152461 DOI: 10.1074/jbc.M009287200

Date:

14-Aug-98 Release date: 27-Feb-02

Protein chain

P21890  (FENR_NOSSO) -  Ferredoxin--NADP reductase from Nostoc sp. (strain ATCC 29151 / PCC 7119)

Seq: 440 a.a.

Struc: 295 a.a.*

* PDB and UniProt seqs differ at 2 residue positions (black crosses)

Enzyme reactions

• Enzyme class: E.C.1.18.1.2 - ferredoxin--NADP(+) reductase.
• Pathway: Methionine Synthase
• Reaction: 2 reduced [2Fe-2S]-[ferredoxin] + NADP⁺ + H⁺ = 2 oxidized [2Fe-2S]- [ferredoxin] + NADPH
• Cofactor: FAD

FAD (Bound ligand (Het Group name = FAD) corresponds exactly)

Molecule diagrams generated from .mol files obtained from the KEGG ftp site

reference

DOI no: 10.1074/jbc.M009287200

J Biol Chem 276:11902-11912 (2001)

PubMed id: 11152461

Probing the determinants of coenzyme specificity in ferredoxin-NADP+ reductase by site-directed mutagenesis.

M.Medina, A.Luquita, J.Tejero, J.Hermoso, T.Mayoral, J.Sanz-Aparicio, K.Grever, C.Gomez-Moreno.

ABSTRACT

On the basis of sequence and three-dimensional structure comparison between Anabaena PCC7119 ferredoxin-NADP(+) reductase (FNR) and other reductases from its structurally related family that bind either NADP(+)/H or NAD(+)/H, a set of amino acid residues that might determine the FNR coenzyme specificity can be assigned. These residues include Thr-155, Ser-223, Arg-224, Arg-233 and Tyr-235. Systematic replacement of these amino acids was done to identify which of them are the main determinants of coenzyme specificity. Our data indicate that all of the residues interacting with the 2'-phosphate of NADP(+)/H in Anabaena FNR are not involved to the same extent in determining coenzyme specificity and affinity. Thus, it is found that Ser-223 and Tyr-235 are important for determining NADP(+)/H specificity and orientation with respect to the protein, whereas Arg-224 and Arg-233 provide only secondary interactions in Anabaena FNR. The analysis of the T155G FNR form also indicates that the determinants of coenzyme specificity are not only situated in the 2'-phosphate NADP(+)/H interacting region but that other regions of the protein must be involved. These regions, although not interacting directly with the coenzyme, must produce specific structural arrangements of the backbone chain that determine coenzyme specificity. The loop formed by residues 261-268 in Anabaena FNR must be one of these regions.

Selected figure(s)

Figure 9.
Fig. 9. Hydrogen bond network and structural differences in the FNR WT (A) and in the T155G FNR mutant (B). In the native state, OH (Thr-155) is making a bifurcated H-bond with the Leu-263 residue. Two new interactions are created after mutation: O (Leu-263) stabilizes a new interaction with N (Met-266), and O 2 (Gly-267) stabilizes a new interaction with N (Gly-265). This produces a less extended conformation for the 261-268 loop in the mutated enzyme.

Figure 10.
Fig. 10. MOLSCRIPT drawing of the superposition of Anabaena FNR (light) and NADH-cytochrome b[5] reductase (dark) (58) near the position of residue 155. In the NAD^+/H-dependent enzymes, a Gly residue at this position is favored due to the presence of a hairpin-like region (formed by a series of prolines) that will not allow the space for a Thr to occupy position 155 of FNR. On the contrary, the absence of this hairpin in the NADP+/H-dependent enzymes permits the presence of residues such as Thr or Pro at this position. Relevant residues are labeled as chain A in FNR or chain B in cytochrome b[5] reductase.

The above figures are reprinted by permission from the ASBMB: J Biol Chem (2001, 276, 11902-11912) copyright 2001.

Figures were selected by the author.