PDBsum entry 1sox

Oxidoreductase

PDB id: 1sox

Contents

Protein chains

463 a.a. *

Ligands

SO4 ×4

MTE ×2

HEM ×2

GOL

EPE

Metals

_MO ×2

Waters ×822

* Residue conservation analysis

PDB id:

1sox

Name:

Oxidoreductase

Title:

Sulfite oxidase from chicken liver

Structure:

Sulfite oxidase. Chain: a, b. Ec: 1.8.3.1

Source:

Gallus gallus. Chicken. Organism_taxid: 9031. Organ: liver. Organelle: mitochondrion. Cellular_location: mitochondrial intermembrane space

Biol. unit:

Dimer (from PDB file)

Resolution:

1.90Å R-factor: 0.175 R-free: 0.220

Authors:

C.Kisker,H.Schindelin,D.C.Rees

Key ref:

C.Kisker et al. (1997). Molecular basis of sulfite oxidase deficiency from the structure of sulfite oxidase. Cell, 91, 973-983. PubMed id: 9428520 DOI: 10.1016/S0092-8674(00)80488-2

Date:

31-Dec-97 Release date: 29-Apr-98

Protein chains

P07850  (SUOX_CHICK) -  Sulfite oxidase from Gallus gallus

Seq: 459 a.a.

Struc: 463 a.a.*

* PDB and UniProt seqs differ at 7 residue positions (black crosses)

Enzyme reactions

• Enzyme class: E.C.1.8.3.1 - sulfite oxidase.
• Reaction: sulfite + O2 + H2O = sulfate + H2O2

sulfite + O2 + H2O = sulfate + H2O2 (Bound ligand (Het Group name = SO4) corresponds exactly)

• Cofactor: Heme; Mo cation

Heme (Bound ligand (Het Group name = HEM) matches with 95.45% similarity) Mo cation

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

reference

DOI no: 10.1016/S0092-8674(00)80488-2

Cell 91:973-983 (1997)

PubMed id: 9428520

Molecular basis of sulfite oxidase deficiency from the structure of sulfite oxidase.

C.Kisker, H.Schindelin, A.Pacheco, W.A.Wehbi, R.M.Garrett, K.V.Rajagopalan, J.H.Enemark, D.C.Rees.

ABSTRACT

The molybdenum-containing enzyme sulfite oxidase catalyzes the conversion of sulfite to sulfate, the terminal step in the oxidative degradation of cysteine and methionine. Deficiency of this enzyme in humans usually leads to major neurological abnormalities and early death. The crystal structure of chicken liver sulfite oxidase at 1.9 A resolution reveals that each monomer of the dimeric enzyme consists of three domains. At the active site, the Mo is penta-coordinated by three sulfur ligands, one oxo group, and one water/hydroxo. A sulfate molecule adjacent to the Mo identifies the substrate binding pocket. Four variants associated with sulfite oxidase deficiency have been identified: two mutations are near the sulfate binding site, while the other mutations occur within the domain mediating dimerization.

Selected figure(s)

Figure 2.
Figure 2. Structure of Sulfite Oxidase(A) The monomer with the N-terminal domain drawn in red, the Mo-co domain in yellow, and the C-terminal domain in green. The N and the C termini are labeled with N and C, respectively. The dotted line between domains I and II indicates the loop region, which is only weakly defined in the electron density. The Mo-co and the heme are shown in ball-and-stick representation with the Fe atom in purple and the Mo atom in green. Figure 2 and Figure 3B have been generated with the programs MOLSCRIPT ( [30]) and RASTER3D ( [1 and 34]).(B) Cα trace of the sulfite oxidase dimer. The gray dotted lines connect the metal centers of the cofactors and indicate the distances between the Mo and Fe within the monomer and the Mo-Mo distance between the two monomers.(C) Interface between the N-terminal and the Mo-co domain. Aliphatic residues are shown in all-bonds representation whereas the heme and residues involved in hydrogen bonding are shown in ball-and-stick representation. Dotted lines indicate hydrogen bonds.

Figure 3.
Figure 3. The Active Site(A) Schematic representation of all protein–cofactor interactions. No water-mediated hydrogen bonds between the cofactor and the protein are observed. Hydrogen bonds are indicated by dashed lines.(B) Stereo view of the active site. All residues are shown in ball-and-stick representation. Atoms which coordinate the Mo are connected to the Mo (green) by a solid line, the view is approximately along the bond between the Mo and the axial oxo ligand.

The above figures are reprinted by permission from Cell Press: Cell (1997, 91, 973-983) copyright 1997.

Figures were selected by an automated process.