fulltext.study @t Gmail

Identification and characterization of another 4-nitrophenol degradation gene cluster, nps, in Rhodococcus sp. strain PN1

Paper ID Volume ID Publish Year Pages File Format Full-Text
21619 43231 2011 8 PDF Available
Title
Identification and characterization of another 4-nitrophenol degradation gene cluster, nps, in Rhodococcus sp. strain PN1
Abstract

4-Nitrophenol (4-NP) is a toxic compound formed in soil by the hydrolysis of organophosphorous pesticides, such as parathion. We previously reported the presence of the 4-NP degradation gene cluster (nphRA1A2) in Rhodococcus sp. strain PN1, which encodes a two-component 4-NP hydroxylase system that oxidizes 4-NP into 4-nitrocatechol. In the current study, another gene cluster (npsC and npsRA2A1B) encoding a similar 4-NP hydroxylase system was cloned from strain PN1. The enzymes from this 4-NP hydroxylase system (NpsA1 and NpsA2) were purified as histidine-tagged (His-) proteins and then characterized. His-NpsA2 showed NADH/FAD oxidoreductase activity, and His-NpsA1 showed 4-NP oxidizing activity in the presence of His-NpsA2. In the 4-NP oxidation using the reconstituted enzyme system (His-NpsA1 and His-NpsA2), hydroquinone (35% of 4-NP disappeared) and hydroxyquinol (59% of 4-NP disappeared) were detected in the presence of ascorbic acid as a reducing reagent, suggesting that, without the reducing reagent, 4-NP was converted into their oxidized forms, 1,4-benzoquinone and 2-hydroxy-1,4-benzoquinone. In addition, in the cell extract of recombinant Escherichia coli expressing npsB, a typical spectral change showing conversion of hydroxyquinol into maleylacetate was observed. These results indicate that this nps gene cluster, in addition to the nph gene cluster, is also involved in 4-NP degradation in strain PN1.

Keywords
4-NP, 4-nitrophenol; 4-NC, 4-nitrocatechol; HQ, hydroquinone; HQL, hydroxyquinol; H12D, HQL 1,2-dioxygenase; His-, histidine-tagged; aa, amino acid4-Nitrophenol; Organophosphorous pesticide; Monooxygenase; Biodegradation; Rhodococcus
First Page Preview
Identification and characterization of another 4-nitrophenol degradation gene cluster, nps, in Rhodococcus sp. strain PN1
Get Full-Text Now
Don't Miss Today's Special Offer
Price was $35.95
You save - $31
Price after discount Only $4.95
100% Money Back Guarantee
Full-text PDF Download
Online Support
Any Questions? feel free to contact us
Publisher
Database: Elsevier - ScienceDirect
Journal: Journal of Bioscience and Bioengineering - Volume 111, Issue 6, June 2011, Pages 687–694
Authors
, , , , ,
Subjects
Physical Sciences and Engineering Chemical Engineering Bioengineering
Get Full-Text Now
Don't Miss Today's Special Offer
Price was $35.95
You save - $31
Price after discount Only $4.95
100% Money Back Guarantee
Full-text PDF Download
Online Support
Any Questions? feel free to contact us