Abstract
This study was carried out to characterize hydroxyquinol 1,2-dioxygenase from Arthrobacter chlorophenolicus A6 (Ar 1,2-HQD). The cphA-I gene encoding Ar 1,2-HQD was cloned and the enzyme was overexpressed for subsequent purification of the recombinant protein by Ni2þ-NTA affinity chromatography and fast protein liquid chromatography (FPLC). Purification of the enzyme by Ni2þ-NTA affinity
chromatography increased the substrate activity for various aromatic hydrocarbon intermediates by 9.4- to 12.9-fold. Subsequent purification of the enzyme by FPLC increased the activity by 51.7- to 65.2-fold. The substrate specificity of Ar 1,2-HQD indicated that the catalytic function of this enzyme is similar to that of the type-II catechol 1,2-dioxygenase (1,2-CTD). The deduced 304 amino acid sequence analysis
also revealed that Ar 1,2-HQD is an intradiol dioxygenase and it is related closely to 1,2-CTD. Its structure consisted of 5 a-helices in the N-terminal domain and 13 b-sheets in the C-terminal domain. The ferric ion was coordinated to two histidine residues and two tyrosine residues. The results of this study suggest that the highly purified Ar 1,2-HQD can be used as a key enzyme in the biodegradation of aromatic
hydrocarbon contaminants.
chromatography increased the substrate activity for various aromatic hydrocarbon intermediates by 9.4- to 12.9-fold. Subsequent purification of the enzyme by FPLC increased the activity by 51.7- to 65.2-fold. The substrate specificity of Ar 1,2-HQD indicated that the catalytic function of this enzyme is similar to that of the type-II catechol 1,2-dioxygenase (1,2-CTD). The deduced 304 amino acid sequence analysis
also revealed that Ar 1,2-HQD is an intradiol dioxygenase and it is related closely to 1,2-CTD. Its structure consisted of 5 a-helices in the N-terminal domain and 13 b-sheets in the C-terminal domain. The ferric ion was coordinated to two histidine residues and two tyrosine residues. The results of this study suggest that the highly purified Ar 1,2-HQD can be used as a key enzyme in the biodegradation of aromatic
hydrocarbon contaminants.
Original language | English |
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Journal | International Biodeterioration & Biodegradation |
ISSN | 0964-8305 |
DOIs | |
Publication status | E-pub ahead of print - 2014 |
Externally published | Yes |
Keywords
- Arthrobacter chlorophenolicus A6
- Aromatic hydrocarbon intermediates
- Enzyme purification
- Hydroxyquinol 1,2-dioxygenase
- Structure characterization