1MJ4: Crystal Structure Analysis Of The Cytochrome B5 Domain Of Human Sulfite Oxidase

The molybdenum- and iron-containing enzyme sulfite oxidase catalyzes the physiologically vital oxidation of sulfite to sulfate. Sulfite oxidase contains three domains: an N-terminal cytochrome b(5) domain, a central domain harboring the molybdenum cofactor (Moco) and a C-terminal dimerization domain. Oxidation of the substrate sulfite is coupled to the transfer of two electrons to the molybdenum cofactor. Subsequently, these electrons are passed on, one at a time, to the b(5) heme of sulfite oxidase and from there to the soluble electron carrier cytochrome c. The crystal structure of the oxidized human sulfite oxidase cytochrome b(5) domain has been determined at 1.2 A resolution and has been refined to a crystallographic R factor of 0.107 (R(free) = 0.137). A comparison of this structure with other b(5)-type cytochromes reveals distinct structural features present in the sulfite oxidase b(5) domain which promote optimal electron transport between the Moco of sulfite oxidase and the heme of cytochrome c.
PDB ID: 1MJ4Download
MMDB ID: 20735
PDB Deposition Date: 2002/8/26
Updated in MMDB: 2007/11
Experimental Method:
x-ray diffraction
Resolution: 1.2  Å
Source Organism:
Similar Structures:
Biological Unit for 1MJ4: monomeric; determined by author
Molecular Components in 1MJ4
Label Count Molecule
Protein (1 molecule)
Sulfite Oxidase(Gene symbol: SUOX)
Molecule annotation
Chemicals (3 molecules)
* Click molecule labels to explore molecular sequence information.

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