Overview for MACiE Entry M0121
EC Number: 18.104.22.168 (A member of the Oxidoreductases, Acting on a sulfur group of donors, With oxygen as acceptor)
Enzyme Name: sulfite oxidase
Biological Species: Gallus gallus (Chicken)
Catalytic Chain UniprotKB Accession Codes:
Representative PDB Code: 1sox - SULFITE OXIDASE FROM CHICKEN LIVER (Resolution = 1.90 Å).
Catalytic CATH Codes:
"Other" CATH Codes:
Display structure information
It is unknown whether this reaction is reversible or not.
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Stepwise Description of the Reaction
|Step 1||Sulfite initiates a nucleophilic attack upon one of the oxo groups coordinated to the Mo(VI) centre in an addition reaction, resulting in a two electron reduction of the centre to Mo(IV).|
|Step 2||Water displaces the sulfate as a ligand to the Mo(IV) centre.|
|Step 3||Water deprotonates Tyr322, which deprotonates the Mo-bound water causing a single electron to be transferred from the Mo(IV) centre to Haem and thence to ferricyrochrome C.|
|Step 4||Water deprotonates Tyr322, which deprotonates the Mo-bound hydroxide causing a single electron to be transferred from the Mo(V) centre to Haem and thence to ferricyrochrome C and regenerating the cofactor.|
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Catalytic Residues Involved
||Location of Function
Metal Cofactors for M0121
- C. Feng et al. (2003), J. Biol. Chem., 278, 2913-2920. Role of conserved tyrosine 343 in intramolecular electron transfer in human sulfite oxidase.
- C. Kisker et al. (1997), Annu. Rev. Biochem., 66, 233-267. Molybdenum-cofactor-containing enzymes: structure and mechanism.
Homologue information for M0121 (1sox)
MACiE Homologues (within the PDB)
MACiE Homologues (within UniprotKB/SwissProt)
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