PDBsum entry 3fg2

Oxidoreductase

PDB id: 3fg2

Contents

Protein chain

404 a.a. *

Ligands

FAD

GOL

Waters ×219

* Residue conservation analysis

PDB id:

3fg2

Name:

Oxidoreductase

Title:

Crystal structure of ferredoxin reductase for the cyp199a2 system from rhodopseudomonas palustris

Structure:

Putative rubredoxin reductase. Chain: p. Synonym: ferredoxin reductase. Engineered: yes

Source:

Rhodopseudomonas palustris. Organism_taxid: 1076. Gene: rpa3782. Expressed in: escherichia coli. Expression_system_taxid: 562.

Resolution:

2.20Å R-factor: 0.213 R-free: 0.255

Authors:

F.Xu

Key ref:

F.Xu et al. (2009). Crystal structure of a ferredoxin reductase for the CYP199A2 system from Rhodopseudomonas palustris. Proteins, 77, 867-880. PubMed id: 19626710

Date:

04-Dec-08 Release date: 01-Sep-09

Protein chain

Q6N3B2  (Q6N3B2_RHOPA) -  Rubredoxin reductase from Rhodopseudomonas palustris (strain ATCC BAA-98 / CGA009)

Seq: 405 a.a.

Struc: 404 a.a.

Enzyme reactions

• Enzyme class: E.C.1.18.1.3 - ferredoxin--NAD(+) reductase.
• Reaction:
  1. 2 reduced [2Fe-2S]-[ferredoxin] + NAD⁺ + H⁺ = 2 oxidized [2Fe- 2S]-[ferredoxin] + NADH
  2. reduced 2[4Fe-4S]-[ferredoxin] + NAD⁺ + H⁺ = oxidized 2[4Fe-4S]- [ferredoxin] + NADH
• Cofactor: FAD

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

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

reference

Proteins 77:867-880 (2009)

PubMed id: 19626710

Crystal structure of a ferredoxin reductase for the CYP199A2 system from Rhodopseudomonas palustris.

F.Xu, S.G.Bell, Y.Peng, E.O.Johnson, M.Bartlam, Z.Rao, L.L.Wong.

ABSTRACT

Cytochrome P450-199A2 from Rhodopseudomonas palustris oxidizes para-substituted benzoic acids and may play a role in lignin and aromatic acid degradation pathways in the bacterium. CYP199A2 has an associated [2Fe-2S] ferredoxin, palustrisredoxin (Pux) but not a ferredoxin reductase. A genome search identified the palustrisredoxin reductase (PuR) gene. PuR was produced in Escherichia coli and shown to be a flavin-dependent protein that supports efficient electron transfer from NADH to Pux, thus reconstituting CYP199A2 monooxygenase activity (k(cat) = 37.9 s(-1) with 4-methoxybenzoic acid). The reduction of Pux by PuR shows K(m) = 4.2 microM and k(cat) = 262 s(-1) in 50 mM Tris, pH 7.4. K(m) is increased to 154 microM in the presence of 200 mM KCl, indicating the importance of ionic interactions in PuR/Pux binding. The crystal structure of PuR has been determined at 2.2 A resolution and found to be closely related to that of other oxygenase-coupled NADH-dependent ferredoxin reductases. Residues on the surface that had been proposed to be involved in ferredoxin reductase-ferredoxin binding are conserved in PuR. However, Lys328 in PuR lies over the FAD isoalloxazine ring and, together with His11 and Gln41, render the electrostatic potential of the surface more positive and may account for the greater involvement of electrostatic interactions in ferredoxin binding by PuR. Consistent with these observations the K328G mutation weakened Pux binding and virtually eliminated the dependence of PuR/Pux binding on salt concentration, thus confirming that the FAD si side surface in the vicinity of Lys328 is the ferredoxin binding site.