Overview for MACiE Entry M0113
EC Number: 184.108.40.206 (A member of the Oxidoreductases, Acting on the CH-NH group of donors, With oxygen as acceptor)
Enzyme Name: sarcosine oxidase
Biological Species: Bacillus sp. (Bacteria)
Catalytic Chain UniprotKB Accession Codes:
- P40859 - Monomeric sarcosine oxidase
Representative PDB Code: 2gb0 - MONOMERIC SARCOSINE OXIDASE: STRUCTURE OF A COVALENTLY FLAVINYLATEDAMINE OXIDIZING ENZYME (Resolution = 1.85 Å).
Catalytic CATH Codes:
"Other" CATH Codes:
Display structure information
It is unknown whether this reaction is reversible or not.
Overall Comment: There are three proposed mechanisms for this enzyme. The hydride transfer mechanism is already shown in entry the homologous enzyme D-amino-acid oxidase (M0110). The polar mechanism is shown here and the single electron transfer mechanism is not shown. There is no strong evidence for any of these alternative mechanisms. The mechanism by which Cys315 becomes attached to FAD involves His45 and Arg49 . This covalent attachment is essential to the enzyme's activity and is thought to function by modulating the redox potential of the FAD and holding the weakly bound FAD in the active site .
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Stepwise Description of the Reaction
|Step 1||The secondary amine of sarcosine initiates a nucleophilic attack on the C4a of FAD in an addition reaction. N5 deprotonates water, which deprotonates Thr48 that regains its proton from bulk solvent through a chain of water molecules.|
|Step 2||His269 deprotonates the terminal methyl group of the FAD-bound sarcosine, eliminating reduced FAD.|
|Step 3||The FAD undergoes double bond rearrangement which causes a single electron to be transferred to a dioxygen molecule.|
|Step 4||The dioxygen molecule undergoes a homolytic reaction in which it colligates to FAD, with concomitant deprotonation of His269.|
|Step 5||The peroxo group deprotonates FAD, which initiates the elimination of hydrogen peroxide.|
|Step 6||The product of the enzyme undergoes spontaneous hydrolysis outside of the active site to produce formaldehyde and glycine.|
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Catalytic Residues Involved
||Location of Function
Organic Cofactors for M0113
- P. Trickey et al. (1999), Structure, 7, 331-345. Monomeric sarcosine oxidase: structure of a covalently flavinylated amine oxidizing enzyme.
- A. Hassan-Abdallah et al. (2006), Biochemistry, 45, 9454-9462. Role of the covalent flavin linkage in monomeric sarcosine oxidase.
Homologue information for M0113 (2gb0)
MACiE Homologues (within the PDB)
MACiE Homologues (within UniprotKB/SwissProt)
Entries with at least one Catalytic CATH code in common (different mechanisms):
|M0294 ||succinate dehydrogenase (ubiquinone) |
|M0020 ||succinate dehydrogenase |
|M0006 ||glutathione-disulfide reductase |
|M0123 ||adenylyl-sulfate reductase |
|M0131 ||4-hydroxybenzoate 3-monooxygenase |
|M0142 ||ferredoxin-NADP+ reductase |
View a comparison of the other reactions in MACiE with the CATH domain 220.127.116.11
View a comparison of the other reactions in MACiE with the CATH domain 18.104.22.168
Links to this entry in other databases