maoB, a gene that encodes a positive regulator of the monoamine oxidase gene (maoA) in Escherichia coli

Yamashita, Mitsuo; Azakami, Hiroyuki; Yokoro, Natsuko; Roh, Jung Hyeob; Suzuki, Hideyuki; Kumagai, Hiroo; Murooka, Yoshikatsu

doi:10.1128/jb.178.10.2941-2947.1996

Cited by 29 publications

(32 citation statements)

References 60 publications

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“…Thus, the catabolite repression of the Pmao A promoter, rather than being a direct effect on such promoter, may reflect the catabolite repression of the maoB gene (342). By using crp cya E. coli mutant strains that contained the maoB::lacZ fusion, it was shown that the catabolite repression by glucose was mediated by the cyclic AMP (cAMP)-CRP complex on the Pmao B promoter (Fig.…”

Section: Transcriptional Activatorsmentioning

confidence: 99%

“…Amino acid sequence comparisons reveal that MaoB is also a member of the AraC family of regulators, having 22% sequence identity to the other AraC family member involved in catabolism of aromatics in E. coli, i.e., the HpaA protein (see above). The significant similarity between the C-terminal domain of MaoB and that of other members of the AraC family suggests that this domain binds to specific DNA in the maoA and padA promoters (Pmao A and Ppad), with the nonhomologous N-terminal and central region of MaoB being involved in the recognition of the inducer molecules, that is, tyramine and PEA (127,342) (Fig. 6A).…”

Section: Transcriptional Activatorsmentioning

confidence: 99%

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Biodegradation of Aromatic Compounds by Escherichia coli

Dı́az

Ferrández

Prieto

et al. 2001

Microbiol Mol Biol Rev

322

235

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Although Escherichia coli has long been recognized as the best-understood living organism, little was known about its abilities to use aromatic compounds as sole carbon and energy sources. This review gives an extensive overview of the current knowledge of the catabolism of aromatic compounds by E. coli. After giving a general overview of the aromatic compounds that E. coli strains encounter and mineralize in the different habitats that they colonize, we provide an up-to-date status report on the genes and proteins involved in the catabolism of such compounds, namely, several aromatic acids (phenylacetic acid, 3- and 4-hydroxyphenylacetic acid, phenylpropionic acid, 3-hydroxyphenylpropionic acid, and 3-hydroxycinnamic acid) and amines (phenylethylamine, tyramine, and dopamine). Other enzymatic activities acting on aromatic compounds in E. coli are also reviewed and evaluated. The review also reflects the present impact of genomic research and how the analysis of the whole E. coli genome reveals novel aromatic catabolic functions. Moreover, evolutionary considerations derived from sequence comparisons between the aromatic catabolic clusters of E. coli and homologous clusters from an increasing number of bacteria are also discussed. The recent progress in the understanding of the fundamentals that govern the degradation of aromatic compounds in E. coli makes this bacterium a very useful model system to decipher biochemical, genetic, evolutionary, and ecological aspects of the catabolism of such compounds. In the last part of the review, we discuss strategies and concepts to metabolically engineer E. coli to suit specific needs for biodegradation and biotransformation of aromatics and we provide several examples based on selected studies. Finally, conclusions derived from this review may serve as a lead for future research and applications

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Section: Transcriptional Activatorsmentioning

confidence: 99%

Section: Transcriptional Activatorsmentioning

confidence: 99%

Biodegradation of Aromatic Compounds by Escherichia coli

Dı́az

Ferrández

Prieto

et al. 2001

Microbiol Mol Biol Rev

322

235

View full text Add to dashboard Cite

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“…As observed for the MhpR regulator, CRP also regulates expression of other transcription factors in E. coli such as MelR (Webster et al, 1988), MalT (Chapon & Kolb, 1983), RhaS (Wickstrum et al, 2005), MaoB (Yamashita et al, 1996), HcaR (Turlin et al, 2001), GalS (Weickert & Adhya, 1993), RpoH (Kallipolitis & Valentin-Hansen, 1998), BlgG (Gulati & Mahadevan, 2000), PrpR (Lee et al, 2005) and Fis (Nasser et al, 2001). …”

Section: Discussionmentioning

confidence: 99%

Escherichia coli mhpR gene expression is regulated by catabolite repression mediated by the cAMP–CRP complex

2011

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The expression of the mhp genes involved in the degradation of the aromatic compound 3-(3-hydroxyphenyl)propionic acid (3HPP) in Escherichia coli is dependent on the MhpR transcriptional activator at the Pa promoter. This catabolic promoter is also subject to catabolic repression in the presence of glucose mediated by the cAMP-CRP complex. The Pr promoter drives the MhpR-independent expression of the regulatory gene. In vivo and in vitro experiments have shown that transcription from the Pr promoter is downregulated by the addition of glucose and this catabolic repression is also mediated by the cAMP-CRP complex. The activation role of the cAMP-CRP regulatory system was further investigated by DNase I footprinting assays, which showed that the cAMP-CRP complex binds to the Pr promoter sequence, protecting a region centred at position "40.5, which allowed the classification of Pr as a class II CRP-dependent promoter. Open complex formation at the Pr promoter is observed only when RNA polymerase and cAMP-CRP are present. Finally, by in vitro transcription assays we have demonstrated the absolute requirement of the cAMP-CRP complex for the activation of the Pr promoter. INTRODUCTIONThe mhp gene cluster of Escherichia coli, which encodes the 3-hydroxyphenylpropionate (3HPP) catabolic pathway, constitutes a model system for studying bacterial degradation because of its distinctive regulation. The mhp regulatory region contains the Pr and Pa promoters, which control the expression of the divergently transcribed mhpR regulatory gene and mhp catabolic genes, respectively (Ferrández et al., 1997). Expression of the mhp catabolic genes depends on the transcriptional activator MhpR, which belongs to the IclR family of transcriptional regulators. MhpR behaves as a 3HPP-dependent activator of the Pa promoter by binding to its specific operator sequence centred at position 258 with respect to the transcription start site in the Pa promoter (Fig. 1a) (Ferrández et al., 1997;Torres et al., 2003). MhpR displays a distinctive regulation mechanism in which phenylpropionic acid activates the MhpR regulator synergistically with the true inducers, representing the first case of such an unusual synergistic effect described for a bacterial regulator (Manso et al., 2009). Gene expression from the Pa promoter is also under a strict global control system mediated by the cAMP-CRP complex that allows expression of the mhp catabolic genes when glucose is not available and 3HPP is present in the medium (Torres et al., 2003). The Pa promoter contains a potential CRP-binding site centred at position 295.5 relative to the transcription start point of Pa (Fig. 1a). In vitro experiments revealed that the specific activator, MhpR, is essential for the recruitment of CRP at the Pa promoter (Torres et al., 2003). The synergistic transcription activation by the cAMP-CRP complex and the MhpR activator allowed the Pa promoter of the mhp cluster to be classified as a class III CRP-dependent promoter (Torres et al., 2003).Although the regulation of the mh...

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“…CRP Mediates a Superimposed Level of Regulation on the Pa Promoter-It is known that some aromatic catabolic pathways in E. coli, such as the paa, hca, hpa, and mao-encoded pathways responsible for the catabolism of phenylacetate, phenylpropionate, 4-hydroxyphenylacetate, and 2-phenylethylamine, respectively, are repressed by the presence of glucose in the culture medium (26,27,(42)(43)(44)(45). To check whether the mhp cluster is also under catabolite repression control, E. coli AFM-CRAL cells were grown in glycerol-or glucose-containing minimal medium in the presence of 3HPP.…”

Section: In Vivo Characterization Of the Pa And Pr Promoters Andmentioning

confidence: 99%

Regulation of the mhp Cluster Responsible for 3-(3-Hydroxyphenyl)propionic Acid Degradation in Escherichia coli

Torres¹,

Porras

Garcı́a

et al. 2003

Journal of Biological Chemistry

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The mhp gene cluster from Escherichia coli constitutes a model system to study bacterial degradation of 3-(3-hydroxyphenyl)propionic acid (3HPP). In this work the regulation of the inducible mhp catabolic genes has been studied by genetic and biochemical approaches. The Pr and Pa promoters, which control the expression of the divergently transcribed mhpR regulatory gene and mhp catabolic genes, respectively, show a peculiar arrangement leading to transcripts that are complementary at their 5 -ends. By using Pr-lacZ and Pa-lacZ translational fusions and gel retardation assays, we have shown that the mhpR gene product behaves as a 3HPP-dependent activator of the Pa promoter, being the expression from Pr constitutive and MhpR-independent. DNase I footprinting experiments and mutational analysis mapped an MhpR-protected region, centered at position ؊58 with respect to the Pa transcription start site, which is indispensable for MhpR binding and in vivo activation of the Pa promoter. Superimposed in the specific MhpR-mediated regulation of the Pa promoter, we have observed a strict catabolite repression control carried out by the cAMP receptor protein (CRP) that allows expression of the mhp catabolic genes when the preferred carbon source (glucose) is not available and 3HPP is present in the medium. Gel retardation assays revealed that the specific activator, MhpR, is essential for the binding of the second activator, CRP, to the Pa promoter. Such peculiar synergistic transcription activation has not yet been observed in other aromatic catabolic pathways, and the MhpR activator becomes the first member of the IclR family of transcriptional regulators that is indispensable for recruiting CRP to the target promoter.

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maoB, a gene that encodes a positive regulator of the monoamine oxidase gene (maoA) in Escherichia coli

Cited by 29 publications

References 60 publications

Biodegradation of Aromatic Compounds by Escherichia coli

Biodegradation of Aromatic Compounds by Escherichia coli

Escherichia coli mhpR gene expression is regulated by catabolite repression mediated by the cAMP–CRP complex

Regulation of the mhp Cluster Responsible for 3-(3-Hydroxyphenyl)propionic Acid Degradation in Escherichia coli

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