Taurine dioxygenase

taurine dioxygenase
Identifiers
EC no.	1.14.11.17
Databases
IntEnz	IntEnz view
BRENDA	BRENDA entry
ExPASy	NiceZyme view
KEGG	KEGG entry
MetaCyc	metabolic pathway
PRIAM	profile
PDB structures	RCSB PDB PDBe PDBsum
Gene Ontology	AmiGO / QuickGO
Search PMC articles PubMed articles NCBI proteins

In enzymology, a taurine dioxygenase (EC 1.14.11.17) is an enzyme that catalyzes the chemical reaction.

taurine + 2-oxoglutarate + O₂${\displaystyle \rightleftharpoons }$ sulfite + aminoacetaldehyde + succinate + CO₂

The 3 substrates of this enzyme are taurine, 2-oxoglutarate, and O₂, whereas its 4 products are sulfite, aminoacetaldehyde, succinate, and CO₂. ^[1]

This enzyme belongs to the family of oxidoreductases, specifically those acting on paired donors, with O2 as oxidant and incorporation or reduction of oxygen. The oxygen incorporated need not be derived from O2 with 2-oxoglutarate as one donor, and incorporation of one atom o oxygen into each donor. The systematic name of this enzyme class is taurine, 2-oxoglutarate:O2 oxidoreductase (sulfite-forming). Other names in common use include 2-aminoethanesulfonate dioxygenase, and alpha-ketoglutarate-dependent taurine dioxygenase. This enzyme participates in taurine and hypotaurine metabolism. It has 3 cofactors: iron, Ascorbate, and Fe2+.

Structural studies

As of late 2007, 4 structures have been solved for this class of enzymes, with PDB accession codes 1GQW, 1GY9, 1OS7, and 1OTJ.

Mechanism

Initiating steps

In the decomposition of taurine, it has been shown that molecular oxygen is activated by Iron II, which lies in the coordinating complex of taurine dioxygenase. ^[2]  Here the enzyme with conjunction of an Iron II and 2-oxoglutarate maintain non-covalent bonds by electrostatic interactions, and coordinate a nucleophilic attack from dioxygen on 2-oxoglutarate carbon number 2. ^[3] This leads to the two oxidations, one on 2-oxoglutarate, and another on taurine, each one electron.

References

1. Elkins JM, Ryle MJ, Clifton IJ, Dunning Hotopp JC, Lloyd JS, Burzlaff NI, et al. (April 2002). "X-ray crystal structure of Escherichia coli taurine/alpha-ketoglutarate dioxygenase complexed to ferrous iron and substrates". Biochemistry. 41 (16): 5185–5192. doi:10.1021/bi016014e. PMID   11955067.
2. Ryle MJ, Koehntop KD, Liu A, Que L, Hausinger RP (April 2003). "Interconversion of two oxidized forms of taurine/α-ketoglutarate dioxygenase, a non-heme iron hydroxylase: Evidence for bicarbonate binding". Proceedings of the National Academy of Sciences of the United States of America. 100 (7): 3790–3795. doi: 10.1073/pnas.0636740100 . PMC   153000 . PMID   12642663.
3. Hibi M, Ogawa J (May 2014). "Characteristics and biotechnology applications of aliphatic amino acid hydroxylases belonging to the Fe(II)/α-ketoglutarate-dependent dioxygenase superfamily". Applied Microbiology and Biotechnology. 98 (9): 3869–3876. doi:10.1007/s00253-014-5620-z. PMID   24682483.

Further reading

• Eichhorn E, van der Ploeg JR, Kertesz MA, Leisinger T (September 1997). "Characterization of alpha-ketoglutarate-dependent taurine dioxygenase from Escherichia coli". The Journal of Biological Chemistry. 272 (37): 23031–23036. doi: 10.1074/jbc.272.37.23031 . PMID   9287300.