4-Oxalocrotonate tautomerase

Available protein structures:
Pfam	structures / ECOD
PDB	RCSB PDB; PDBe; PDBj
PDBsum	structure summary
PDB	PDB: 1bjp PDB: 1gyj PDB: 1gyx PDB: 1gyy PDB: 1otf PDB: 1s0y PDB: 4ota PDB: 4otb PDB: 4otc

4-oxalocrotonate tautomerase
Identifiers
Symbol	Taut
Pfam	PF01361
InterPro	IPR004370
CDD	cd00491
Available protein structures:
Pfam	structures / ECOD
PDB	RCSB PDB; PDBe; PDBj
PDBsum	structure summary
PDB	PDB: 1bjp PDB: 1gyj PDB: 1gyx PDB: 1gyy PDB: 1otf PDB: 1s0y PDB: 4ota PDB: 4otb PDB: 4otc

4-Oxalocrotonate tautomerase (EC 5.3.2.-4-OT) is an enzyme that converts 2-hydroxymuconate to the αβ-unsaturated ketone, 2-oxo-3-hexenedioate.^[1] This enzyme forms part of a bacterial metabolic pathway that oxidatively catabolizes toluene, o-xylene, 3-ethyltoluene, and 1,2,4-trimethylbenzene into intermediates of the citric acid cycle. With a monomer size of just 62 amino acid residues, the 4-Oxalocrotonate tautomerase is one of the smallest enzyme subunits known.^[2] However, in solution, the enzyme forms a hexamer of six identical subunits, so the active site may be formed by amino acid residues from several subunits.^[3] This enzyme is also unusual in that it uses a proline residue at the amino terminus as an active site residue.

References

^ Chen LH, Kenyon GL, Curtin F, Harayama S, Bembenek ME, Hajipour G, Whitman CP (September 1992). "4-Oxalocrotonate tautomerase, an enzyme composed of 62 amino acid residues per monomer". The Journal of Biological Chemistry. 267 (25): 17716–21. PMID 1339435.
^ Whitman CP (June 2002). "The 4-oxalocrotonate tautomerase family of enzymes: how nature makes new enzymes using a beta-alpha-beta structural motif". Archives of Biochemistry and Biophysics. 402 (1): 1–13. doi:10.1016/S0003-9861(02)00052-8. PMID 12051677.
^ Subramanya HS, Roper DI, Dauter Z, Dodson EJ, Davies GJ, Wilson KS, Wigley DB (January 1996). "Enzymatic ketonization of 2-hydroxymuconate: specificity and mechanism investigated by the crystal structures of two isomerases". Biochemistry. 35 (3): 792–802. doi:10.1021/bi951732k. PMID 8547259.

[1] Chen LH, Kenyon GL, Curtin F, Harayama S, Bembenek ME, Hajipour G, Whitman CP (September 1992). "4-Oxalocrotonate tautomerase, an enzyme composed of 62 amino acid residues per monomer". The Journal of Biological Chemistry. 267 (25): 17716–21. PMID 1339435.

[2] Whitman CP (June 2002). "The 4-oxalocrotonate tautomerase family of enzymes: how nature makes new enzymes using a beta-alpha-beta structural motif". Archives of Biochemistry and Biophysics. 402 (1): 1–13. doi:10.1016/S0003-9861(02)00052-8. PMID 12051677.

[pmid8547259-3] Subramanya HS, Roper DI, Dauter Z, Dodson EJ, Davies GJ, Wilson KS, Wigley DB (January 1996). "Enzymatic ketonization of 2-hydroxymuconate: specificity and mechanism investigated by the crystal structures of two isomerases". Biochemistry. 35 (3): 792–802. doi:10.1021/bi951732k. PMID 8547259.

[1]

[2]

[3]