PDBsum entry 1b2r

Oxidoreductase

PDB id: 1b2r

Contents

Protein chain

295 a.a. *

Ligands

SO4

FAD

Waters ×657

* Residue conservation analysis

PDB id:

1b2r

Name:

Oxidoreductase

Title:

Ferredoxin-NADP+ reductase (mutation: e 301 a)

Structure:

Protein (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:

1.80Å R-factor: 0.190 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:

T.Mayoral et al. (2000). Structural basis of the catalytic role of Glu301 in Anabaena PCC 7119 ferredoxin-NADP+ reductase revealed by x-ray crystallography. Proteins, 38, 60-69. PubMed id: 10651039 DOI: 10.1002/(SICI)1097-0134(20000101)38:1<60::AID-PROT7>3.3.CO;2-2

Date:

27-Nov-98 Release date: 15-Dec-99

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: 10.1002/(SICI)1097-0134(20000101)38:1<60::AID-PROT7>3.3.CO;2-2

Proteins 38:60-69 (2000)

PubMed id: 10651039

Structural basis of the catalytic role of Glu301 in Anabaena PCC 7119 ferredoxin-NADP+ reductase revealed by x-ray crystallography.

T.Mayoral, M.Medina, J.Sanz-Aparicio, C.Gómez-Moreno, J.A.Hermoso.

ABSTRACT

The three-dimensional crystal structure of the Glu301Ala site-directed mutant of ferredoxin-NADP+ reductase from Anabaena PCC 7119 has been determined at 1.8A resolution by x-ray diffraction. The overall folding of the Glu301Ala FNR mutant shows no significant differences with respect to that of the wild-type enzyme. However, interesting conformational changes are detected in the side chain of another glutamate residue, Glu139, which now points towards the FAD cofactor in the active center cavity. The new conformation of the Glu139 side chain is stabilized by a network of five hydrogen bonds to several water molecules, which seem to hold the carboxylate side chain in a rather fixed position. This interacting network connects the Glu139 side chain to the Ser80 side chain through a series of three water molecules. These observations are discussed in terms of the reactivity of Glu301Ala ferredoxin-NADP+ reductase towards its substrates, and the role of Glu301 in the catalysis is re-examined. Moreover, a structural explanation of the different reoxidation properties of this mutant is given on the basis of the reported structure by modeling the hypothetical flavin C(4a)-hydroperoxide intermediate. The model shows that the distal oxygen of the peroxide anion could be in an appropriate situation to act as the proton donor in the reoxidation process.

Selected figure(s)

Figure 4.
Figure 4. A section of the molecular surface near the FAD group (represented as CPK and seen approximately in the same orientation) in (a) FNR wild-type enzyme and in (b) the Glu301Ala FNR. A new pocket is formed next to the FAD group increasing the solvent accessibility surface by 8 Å.[2] The C4a atom of isoalloxazine ring is highlighted (see Fig. 5 for labeling).

Figure 5.
Figure 5. The flavin-C(4a)-hydroperoxide model. a: Schematic diagram. b: Stereo view of the superposition of the flavin-C(4a)-hydroperoxide model (dashed lines) and the flavin ring of the Glu301Ala FNR structure (solid lines). The arrow indicates the rotation needed to generate the Od allowed region (see text).

The above figures are reprinted by permission from John Wiley & Sons, Inc.: Proteins (2000, 38, 60-69) copyright 2000.

Figures were selected by the author.