Reviewed, UniProtKB/Swiss-Prot Q5PXQ6 (CHQB_NOCSI)

Names and origin

Protein names

Recommended name:
    Hydroxyquinol 1,2-dioxygenase
    EC=1.13.11.37
Alternative name(s):
    1,2-HQD

Gene names

Name:

chqB

Organism

Nocardioides simplex (Arthrobacter simplex)

Taxonomic identifier

2045 [NCBI]

Taxonomic lineage

Bacteria › Actinobacteria › Actinobacteridae › Actinomycetales › Propionibacterineae › Nocardioidaceae › Pimelobacter

Protein attributes

Sequence length	293 AA.
Sequence status	Complete.
Sequence processing	The displayed sequence is not processed.
Protein existence	Evidence at protein level.

General annotation (Comments)

Function	Catalyzes the ortho-cleavage of the aromatic ring of hydroxyquinol.
Catalytic activity	Benzene-1,2,4-triol + O(2) = 3-hydroxy-cis,cis-muconate.
Cofactor	Binds 1 Fe(3+) ion per subunit.
Enzyme regulation	Inhibited by 3,5-dichlorocatechol, chlorohydroquinone and 4,5-dibromocatechol.
Pathway	Aromatic compound metabolism; beta-ketoadipate pathway; 3-oxoadipate from 3,4-dihydroxybenzoate: step 2/4.
Subunit structure	Homodimer.
Sequence similarities	Belongs to the intradiol ring-cleavage dioxygenase family.
Biophysicochemical properties	Kinetic parameters: 5-chlorohydroxyquinols and 6-chloro-chlorohydroxyquinols are also substrates. KM=1.2 µM for hydroxyquinol Vmax=55 µmol/min/mg enzyme with hydroxyquinol as substrate pH dependence: Optimum pH is 7.5. Temperature dependence: Optimum temperature is 50-55 degrees Celsius.

Ontologies

Keywords
Biological process	Aromatic hydrocarbons catabolism
Ligand	Iron Metal-binding
Molecular function	Dioxygenase Oxidoreductase
Technical term	3D-structure Direct protein sequencing
Gene Ontology (GO)
Biological process	aromatic compound catabolic process Inferred from electronic annotation. Source: UniProtKB-KW catechol metabolic process Inferred from electronic annotation. Source: InterPro oxidation reduction Inferred from electronic annotation. Source: UniProtKB-KW
Molecular function	catechol 1,2-dioxygenase activity Inferred from electronic annotation. Source: InterPro ferric iron binding Inferred from electronic annotation. Source: InterPro hydroxyquinol 1,2-dioxygenase activity Inferred from electronic annotation. Source: EC
Complete GO annotation...

Sequence annotation (Features)

Feature key

Position(s)

Length

Description

Graphical view

Feature identifier

Molecule processing

Chain

1 – 293

293

Hydroxyquinol 1,2-dioxygenase

PRO_0000085086

Sites

Metal binding

164

1

Iron

Metal binding

197

1

Iron

Metal binding

221

1

Iron

Metal binding

223

1

Iron

Secondary structure

1

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293

Helix Strand Turn

Details...

Helix

7 – 23

17

Turn

24 – 26

3

Helix

30 – 50

21

Helix

54 – 70

17

Helix

77 – 84

8

Helix

87 – 95

9

Beta strand

133 – 142

10

Beta strand

152 – 156

5

Helix

165 – 167

3

Beta strand

168 – 170

3

Beta strand

175 – 180

6

Beta strand

185 – 192

8

Helix

204 – 211

8

Beta strand

221 – 227

7

Beta strand

234 – 240

7

Helix

244 – 247

4

Helix

256 – 258

3

Beta strand

263 – 265

3

Helix

272 – 274

3

Beta strand

281 – 285

5

Beta strand

288 – 290

3

Sequences

	Sequence		Length	Mass (Da)
	Q5PXQ6-1 [UniParc]. Last modified January 4, 2005. Version 1. Checksum: DEE403CF2AB8F5B0	FASTA	293	31,967
	10 20 30 40 50 60 MSTPVSAEQQ AREQDLVERV LRSFDATADP RLKQVMQALT RHLHAFLREV RLTEAEWETG 70 80 90 100 110 120 IGFLTDAGHV TNERRQEFIL LSDVLGASMQ TIAMNNEAHG DATEATVFGP FFVEGSPRIE 130 140 150 160 170 180 SGGDIAGGAA GEPCWVEGTV TDTDGNPVPD ARIEVWEADD DGFYDVQYDD DRTAARAHLL 190 200 210 220 230 240 SGPDGGYAFW AITPTPYPIP HDGPVGRMLA ATGRSPMRAS HLHFMVTAPG RRTLVTHIFV 250 260 270 280 290 EGDELLDRDS VFGVKDSLVK SFERQPAGAP TPGGREIDGP WSRVRFDIVL APA

References

[1]

"Crystal structure of the hydroxyquinol 1,2-dioxygenase from Nocardioides simplex 3E, a key enzyme involved in polychlorinated aromatics biodegradation." Ferraroni M., Seifert J., Travkin V.M., Thiel M., Kaschabek S., Scozzafava A., Golovleva L., Schloemann M., Briganti F. J. Biol. Chem. 280:21144-21154(2005) [PubMed: 15772073] [Abstract] Cited for: NUCLEOTIDE SEQUENCE [GENOMIC DNA], PARTIAL PROTEIN SEQUENCE, X-RAY CRYSTALLOGRAPHY (1.75 ANGSTROMS) IN COMPLEX WITH FE(III), CHARACTERIZATION. Strain: 3E.

[2]

"Characterization of an intradiol dioxygenase involved in the biodegradation of the chlorophenoxy herbicides 2,4-D and 2,4,5-T." Travkin V.M., Jadan A.P., Briganti F., Scozzafava A., Golovleva L.A. FEBS Lett. 407:69-72(1997) [PubMed: 9141483] [Abstract] Cited for: FUNCTION, BIOPHYSICOCHEMICAL PROPERTIES, SUBUNIT. Strain: 3E.

Cross-references

Sequence databases

EMBLGenBankDDBJ

AY822041 Genomic DNA. Translation: AAV71144.1.

3D structure databases

PDBMSD

Entry	Method	Resolution (Å)	Chain	Positions	PDBsum
1TMX	X-ray	1.75	A/B	1-293	[»]

ModBase

Search...

Family and domain databases

InterPro

IPR007535. Catechol_dOase_N.
IPR000627. Intradiol_dOase_C.
IPR015889. Intradiol_dOase_core.
[Graphical view]

Gene3D

G3DSA:2.60.130.10. Intradiol_dOase_core. 1 hit.

Pfam

PF00775. Dioxygenase_C. 1 hit.
PF04444. Dioxygenase_N. 1 hit.
[Graphical view]

PROSITE

PS00083. INTRADIOL_DIOXYGENAS. 1 hit.
[Graphical view]

ProtoNet

Search...

Entry information

Entry name

CHQB_NOCSI

Accession

Primary (citable) accession number: Q5PXQ6

Entry history

Integrated into UniProtKB/Swiss-Prot:	February 7, 2006
Last sequence update:	January 4, 2005
Last modified:	November 25, 2008
This is version 25 of the entry and version 1 of the sequence. [Complete history]

Entry status

Reviewed (UniProtKB/Swiss-Prot)

Annotation project

HAMAP (High-quality Automated and Manual Annotation of microbial Proteomes)