A monoamine-regulated Klebsiella aerogenes operon containing the monoamine oxidase structural gene (maoA) and the maoC gene

Abstract

The Klebsiella aerogenes gene maoA, which is involved in the synthesis of monoamine oxidase, was induced by tyramine and the related compounds, subjected to catabolite and ammonium ion repression, and cloned. The nucleotide sequence of the region involved in monoamine oxidase synthesis was determined. Two open reading frames, the maoA gene and a hitherto unknown gene (maoC), were found. These are located between a potential promoter sequence and a transcriptional terminator sequence. A region of the Escherichia coli chromosome that was highly homologous to the KiebsieUla maoA gene was found. The potential maoA gene is located at 30.9 min on the E. coli chromosome. Analysis of the amino acid sequences of the first 11 amino acids from the N terminus of the purified monoamine oxidase agrees with those deduced from the nucleotide sequence of the maoA gene. The leader peptide extends over 30 amino acids and has the characteristics of a signal sequence. Primer extension and S1 nuclease mapping of transcripts generated in vivo suggests that the tyramine-induced mRNA starts at a site 62 bases upstream from the ATG initiation codon of the maoC gene.In the putative promoter region, a high degree of similarity to the consensus sequence for the binding site of cyclic AMP receptor protein was found. Thus, the mao region is composed of two cistrons, and the mao operon is regulated by monoamine compounds, glucose, and ammonium ions.

Regulation of yodA encoding a novel cadmium-induced protein in Escherichia coli The GenBank accession number for the E. coli yodA gene and the SWISS-PROT accession number for E. coli YodA protein in this paper are AAC75039 and P76344, respectively.

“…et al, 2001), which is a lipoprotein containing a putative metal-binding site . In addition, YodA exhibits weak sequence similarity with the N-terminal part (about 200 aa) of the copper-binding protein amine oxidase, encoded by maoA (Ferianc et al, 1998), of both E. coli (Azakami et al, 1994) and Klebsiella aerogenes (Sugino et al, 1992). In this work we have identified the yodA promoter and report that induction of the gene during cadmium exposure is dependent on soxS, fur and relA\spoT of the stringent response, but not oxyR.…”

Identification and Characterization of a New Enoyl Coenzyme A Hydratase Involved in Biosynthesis of Medium-Chain-Length Polyhydroxyalkanoates in Recombinant Escherichia coli

“…The maoC gene exists as an operon with the maoA gene in E. coli (31,32). The mao operon has been reported to encode enzymes involved in the degradation of aromatic amine compounds.…”

Biodegradation of Aromatic Compounds by Escherichia coli

“…The maoA, padA, and maoB genes (alternative gene names, tynA, feaB, and feaR, respectively) have been sequenced in E. coli K-12 and W strains and are located at 31.1 min on the chromosome (94,127,307). The padA gene is transcribed in the opposite direction to that of maoA and maoB (Fig.…”

“…65,2001 BIODEGRADATION OF AROMATIC COMPOUNDS BY E. COLI 541 acterize the aldehyde dehydrogenase superfamily of proteins (94,237). The amino acid sequence of the C-terminal region of PaaZ shows high similarity (97%) to the last 157 aa of MaoC from K. aerogenes, a protein that was predicted to be a regulatory element (307). Nevertheless, translation of the maoC gene can be extended toward the 5Ј end of the reported sequence, revealing a single protein that is homologous to PaaZ.…”