Crystal structure of an aerobic FMN-dependent azoreductase (AzoA) from Enterococcus faecalis

Liu, Zhijie; Chen, Huizhong; Shaw, Neil; Hopper, Sherryll L.; Chen, Lirong; Chen, Siwei; Cerniglia, Carl E.; Wang, Bi-Cheng

doi:10.1016/j.abb.2007.03.003

Cited by 64 publications

(52 citation statements)

References 34 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Based on flavin cofactor content and nicotinamide dependence or preference, azoreductase superfamily can be classified into five major groups-(1) flavin-containing NADH-dependent azoreductase (Matsumoto et al 2010;Liu et al 2007), (2) flavin-containing NADPH-dependent azoreductase (Chen et al 2005;Wang et al 2007), (3) flavin-containing NAD(P)H-dependent azoreductase (Qi et al 2016(Qi et al , 2017aOturkar et al 2013), (4) flavinfree NAD(P)H-dependent azoreductase (Blumel et al 2002;Chen et al 2010;Misal et al 2011Misal et al , 2014Misal et al , 2015, and (5) flavin-containing NAD(P)H-dependent quinone Fig. 1 Azoreduction mechanism of amaranth dye by azoreductase enzyme: The UV-Visible spectrum demonstrating the complete reduction of amaranth dye in 24 h of incubation with purified azoreductase.…”

Section: Azoreductase Classificationmentioning

confidence: 99%

Azoreductase: a key player of xenobiotic metabolism

Misal

Gawai

2018

Bioresour. Bioprocess.

143

View full text Add to dashboard Cite

Azoreductases are diverse flavoenzymes widely present among microorganisms and higher eukaryotes. They are mainly involved in the biotransformation and detoxification of azo dyes, nitro-aromatic, and azoic drugs. Reduction of azo bond and reductive activation of pro-drugs at initial level is a crucial stage in degradation and detoxification mechanisms. Using azoreductase-based microbial enzyme systems that are biologically accepted and ecofriendly demonstrated complete degradation of azo dyes. Azoreductases are flavin-containing or flavin-free group of enzymes, utilizing the nicotinamide adenine dinucleotide or nicotinamide adenine dinucleotide phosphate as a reducing equivalent. Azoreductases from anaerobic microorganisms are highly oxygen sensitive, while azoreductases from aerobic microorganisms are usually oxygen insensitive. They have variable pH, temperature stability, and wide substrate specificity. Azo dyes, nitro-aromatic compounds, and quinones are the known substrates of azoreductase. The present review gives an overview of recent developments in the known azoreductase enzymes from different microorganisms, its novel classification scheme, significant characteristics, and their plausible degradation mechanisms.

show abstract

Section: Azoreductase Classificationmentioning

confidence: 99%

Azoreductase: a key player of xenobiotic metabolism

Misal

Gawai

2018

Bioresour. Bioprocess.

143

View full text Add to dashboard Cite

show abstract

“…Flavin-dependent azoreductases can be further classified into two families according to their amino acid sequences (9,28). Azoreductases from E. coli and Bacillus sp.…”

mentioning

confidence: 99%

The Escherichia coli Azoreductase AzoR Is Involved in Resistance to Thiol-Specific Stress Caused by Electrophilic Quinones

Liu

Wang

2009

J Bacteriol

View full text Add to dashboard Cite

The physiological role of Escherichia coli azoreductase AzoR was studied. It was found that AzoR was capable of reducing several benzo-, naphtho-, and anthraquinone compounds, which were better substrates for AzoR than the model azo substrate methyl red. The ⌬azoR mutant displayed reduced viability when exposed to electrophilic quinones, which are capable of depleting cellular reduced glutathione (GSH). Externally added GSH can partially restore the impaired growth of the ⌬azoR mutant caused by 2-methylhydroquinone. The transcription of azoR was induced by electrophiles, including 2-methylhydroquinone, catechol, menadione, and diamide. A transcription start point was identified 44 bp upstream from the translation start point. These data indicated that AzoR is a quinone reductase providing resistance to thiol-specific stress caused by electrophilic quinones.

show abstract

“…1a). The amino acid residues involved in FMN binding, leu at position 104 and thr residue at position 19 differ from SeMet-O and Ser in AzoA respectively (Liu ZJ et al, 2007. In comparison with the AzoR from Escherichia coli, a 42% identity was observed (Fig.…”

Section: Identification Of the E Faecium Acpd Genementioning

confidence: 81%

Identification and Isolation of an Azoreductase fromEnterococcus faecium

Macwana

Punj²,

Cooper

et al. 2010

Current Issues in Molecular Biology

View full text Add to dashboard Cite

Azo dyes are commonly used in many commercial industries. Some of the azo dyes can produce carcinogenic compounds after being metabolized by azoreductase. Several human intestinal microbiota possess azoreductase activity which plays an important role in the toxicity and mutagenicity of these azo dye compounds. The acpD gene product (AzoEf1) responsible for the azoreductase activity of Enterococcus faecium, an intestinal bacterium, was heterologously expressed, purified and characterized. The protein sequence shares 67% identity with the azoreductase from Enterococcus faecalis, AzoA. Although AzoEf1 possesses many commonalities with AzoA, there are differences in coenzyme preference, residues associated with FMN binding, substrate specificity, and specific activity. AzoEf1 utilized both NADH and NADPH for the reduction of azo dyes, and it contains a leucyl residue at position 104 and threonyl residue at position 19 which differ from AzoA at the active site. Its specific activity was 5095 µM/min/ mg and its catalytic efficiency for Methyl red reduction was lower than AzoA.

show abstract

Crystal structure of an aerobic FMN-dependent azoreductase (AzoA) from Enterococcus faecalis

Cited by 64 publications

References 34 publications

Azoreductase: a key player of xenobiotic metabolism

Azoreductase: a key player of xenobiotic metabolism

The Escherichia coli Azoreductase AzoR Is Involved in Resistance to Thiol-Specific Stress Caused by Electrophilic Quinones

Identification and Isolation of an Azoreductase fromEnterococcus faecium

Contact Info

Product

Resources

About