PDBsum entry 1e6e

Oxidoreductase

PDB id: 1e6e

Contents

Protein chains

457 a.a. *

113 a.a. *

106 a.a. *

Ligands

FAD ×2

SO4 ×5

FES ×2

Waters ×274

* Residue conservation analysis

PDB id:

1e6e

Name:

Oxidoreductase

Title:

Adrenodoxin reductase/adrenodoxin complex of mitochondrial p450 systems

Structure:

Nadph\:adrenodoxin oxidoreductase. Chain: a, c. Synonym: ar, adrenodoxin reductase, ferredoxin--NADP(+) reductase ferredoxin reductase, adr, adrenodoxin reductase. Engineered: yes. Other_details: covalent crosslink between lys27 of adr and asp39 of adx. Adrenodoxin. Chain: b, d.

Source:

Bos taurus. Bovine. Organism_taxid: 9913. Organ: adrenal gland. Tissue: steroidogenic tissues. Cell: mitochondrion. Organelle: mitochondrial matrix. Cellular_location: attached to inner mitochondrial membrane. Expressed in: escherichia coli.

Resolution:

2.30Å R-factor: 0.222 R-free: 0.268

Authors:

J.J.Mueller,A.Lapko,G.Bourenkov,K.Ruckpaul,U.Heinemann

Key ref:

J.J.Müller et al. (2001). Adrenodoxin reductase-adrenodoxin complex structure suggests electron transfer path in steroid biosynthesis. J Biol Chem, 276, 2786-2789. PubMed id: 11053423 DOI: 10.1074/jbc.M008501200

Date:

15-Aug-00 Release date: 09-Aug-01

Protein chains

P08165  (ADRO_BOVIN) -  NADPH:adrenodoxin oxidoreductase, mitochondrial from Bos taurus

Seq: 492 a.a.

Struc: 457 a.a.

Protein chain

P00257  (ADX_BOVIN) -  Adrenodoxin, mitochondrial from Bos taurus

Seq: 186 a.a.

Struc: 113 a.a.

Protein chain

P00257  (ADX_BOVIN) -  Adrenodoxin, mitochondrial from Bos taurus

Seq: 186 a.a.

Struc: 106 a.a.

Enzyme reactions

• Enzyme class: Chains A, C: E.C.1.18.1.6 - adrenodoxin-NADP(+) reductase.
• Reaction: 2 reduced [adrenodoxin] + NADP⁺ + H⁺ = 2 oxidized [adrenodoxin] + 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.M008501200

J Biol Chem 276:2786-2789 (2001)

PubMed id: 11053423

Adrenodoxin reductase-adrenodoxin complex structure suggests electron transfer path in steroid biosynthesis.

J.J.Müller, A.Lapko, G.Bourenkov, K.Ruckpaul, U.Heinemann.

ABSTRACT

The steroid hydroxylating system of adrenal cortex mitochondria consists of the membrane-attached NADPH-dependent adrenodoxin reductase (AR), the soluble one-electron transport protein adrenodoxin (Adx), and a membrane-integrated cytochrome P450 of the CYP11 family. In the 2.3-A resolution crystal structure of the Adx.AR complex, 580 A(2) of partly polar surface are buried. Main interaction sites are centered around Asp(79), Asp(76), Asp(72), and Asp(39) of Adx and around Arg(211), Arg(240), Arg(244), and Lys(27) of AR, respectively. In particular, the region around Asp(39) defines a new protein interaction site for Adx, similar to those found in plant and bacterial ferredoxins. Additional contacts involve the electron transfer region between the redox centers of AR and Adx and C-terminal residues of Adx. The Adx residues Asp(113) to Arg(115) adopt 3(10)-helical conformation and engage in loose intermolecular contacts within a deep cleft of AR. Complex formation is accompanied by a slight domain rearrangement in AR. The [2Fe-2S] cluster of Adx and the isoalloxazine rings of FAD of AR are 10 A apart suggesting a possible electron transfer route between these redox centers. The AR.Adx complex represents the first structure of a biologically relevant complex between a ferredoxin and its reductase.

Selected figure(s)

Figure 1.
Fig. 1. Crystal structure of the AR·Adx complex. AR-Adx contacts occur at the primary and secondary interaction regions and the region between the [2Fe-2S] cluster of Adx and the isoalloxazine ring of the FAD of AR. C-terminal residues of Adx are also in contact with AR. The side chains of some residues involved in polar AR-Adx interactions are displayed. For close-ups of the contact sites see Figs. 3 and 4. The brown triangle marks the position of Adx Lys66 and the green marks AR Glu4, both residues maintaining another cross-link reported recently (11, 12). Figure was produced with MOLSCRIPT (17).

Figure 4.
Fig. 4. Electron transfer region between the [2Fe-2S] cluster of Adx and the FAD moiety of AR. The hypothetical electron pathway shown in red was calculated with the program HARLEM (31). Red dotted lines mark through-space electron jumps. The AR-Adx interface is stabilized by hydrogen bonds (blue dotted lines) and van der Waals contacts. Residues are labeled black for AR and red for Adx. The blue spheres are water molecules.

The above figures are reprinted by permission from the ASBMB: J Biol Chem (2001, 276, 2786-2789) copyright 2001.

Figures were selected by the author.