DB code: S00355

RLCP classification 8.11113.45000.86 : Isomerization
1.51.3100.78 : Hydrolysis
8.11131.365050.86 : Isomerization
CATH domain 3.40.50.1820 : Rossmann fold Catalytic domain
E.C. 3.7.1.8
CSA 1c4x
M-CSA 1c4x
MACiE

CATH domain Related DB codes (homologues)
3.40.50.1820 : Rossmann fold S00544 S00344 S00517 S00525 S00526 S00720 S00723 S00724 S00725 S00919 S00057 S00374 S00345 S00347 S00348 S00346 S00350 S00352 S00353 S00356 S00358 D00189 D00210 D00539 T00253

Uniprot Enzyme Name
UniprotKB Protein name Synonyms
O05149
2-hydroxy-6-oxo-6-phenylhexa-2,4-dienoate hydrolase
Q84II3
Meta cleavage compound hydrolase

KEGG enzyme name
2,6-dioxo-6-phenylhexa-3-enoate hydrolase
HOHPDA hydrolase

UniprotKB: Accession Number Entry name Activity Subunit Subcellular location Cofactor
O05149 O05149_RHOSO
Q84II3 Q84II3_9BURK

KEGG Pathways
Map code Pathways E.C.
MAP00621 Biphenyl degradation
MAP00628 Fluorene degradation

Compound table
Substrates Products Intermediates
KEGG-id C01273 C00001 C00180 C00596
E.C.
Compound 2,6-Dioxo-6-phenylhexa-3-enoate H2O Benzoate 2-Oxopent-4-enoate
Type aromatic ring (only carbon atom),carbohydrate,carboxyl group H2O aromatic ring (only carbon atom),carboxyl group carbohydrate,carboxyl group
ChEBI 15377
 15377
 		30746
 30746
 		1113
 1113
PubChem 22247451
 962
 22247451
 962
 		20144841
 243
 20144841
 243
 		5280361
 5280361
1c4xA Unbound Unbound Unbound
1j1iA Unbound Unbound Unbound

Reference for Active-site residues
resource references E.C.
literature [2]

Active-site residues
PDB Catalytic residues Cofactor-binding residues Modified residues Main-chain involved in catalysis Comment
1c4xA SER 110;ASP 235;HIS 263
1j1iA SER 114;ASP 233;HIS 261

References for Catalytic Mechanism
References Sections No. of steps in catalysis
[2]
p.1144-1146

References
[1]
Resource
Comments
Medline ID
PubMed ID
Journal Proc Jpn Acad Ser B
Year 1997
Volume 73
Pages 154-7
Authors N.Nandhagopal, T.Senda, T.Hatta, A.Yamada, E.Masai, M.Fukuda, Y.Mitsui
Title Three-dimensional structure of microbial 2-hydroxyl-6-oxo-6-phenylhexa-2,4- dienoic acid (hpda) hydrolase (bphd enzyme) from rhodococcussp. Strain rha1, in the pcb degradation pathway.
Related PDB 1c4x
Related UniProtKB
[2]
Resource
Comments X-ray crystallography (2.4 Angstroms)
Medline ID
PubMed ID 11399084
Journal J Mol Biol
Year 2001
Volume 309
Pages 1139-51
Authors Nandhagopal N, Yamada A, Hatta T, Masai E, Fukuda M, Mitsui Y, Senda T
Title Crystal structure of 2-hydroxyl-6-oxo-6-phenylhexa-2,4-dienoic acid (HPDA) hydrolase (BphD enzyme) from the Rhodococcus sp. strain RHA1 of the PCB degradation pathway.
Related PDB 1c4x
Related UniProtKB
[3]
Resource
Comments
Medline ID
PubMed ID 12659866
Journal Biochem Biophys Res Commun
Year 2003
Volume 303
Pages 631-9
Authors Habe H, Morii K, Fushinobu S, Nam JW, Ayabe Y, Yoshida T, Wakagi T, Yamane H, Nojiri H, Omori T
Title Crystal structure of a histidine-tagged serine hydrolase involved in the carbazole degradation (CarC enzyme).
Related PDB 1j1i
Related UniProtKB

Comments
The paper [2] mentioned that, although the catalytic mechanism of this enzyme might be similar to that of other alpha/beta-hydrolases, there is a significant differences between them. The literature mentioned that a chemical modification to the possible nucleophile, Ser110, might play a role in the catalytic mechanism, which can be required to hydrolyze carbon-carbon bonds [2].
Although the literature [2] mentioned that His35/Gly36 (of 1c4x) might form an oxyanion hole, these residues are a bit far from the active site. Instead, comparison with other homologus enzymes (T00253, S00345, S00347, S00350, S00374), which have got Ser/His/Asp as catalytic triad with complex structure determined, suggested that mainchain amide groups of Ala37 and Met111 must form an oxyanion hole.
On the other hand, recent study on the homologous enzyme, which also catalyzes hydrolysis of Ketonic carbon-carbon bond suggested totally different mechanism, which involves isomerization (S00526 in EzCatDB).

Created Updated
2002-07-04 2009-03-30