Sugino H, Sasaki M, Azakami H, Yamashita M, Murooka Y
Department of Fermentation Technology, Faculty of Engineering, Hiroshima University, Japan.
J Bacteriol. 1992 Apr;174(8):2485-92. doi: 10.1128/jb.174.8.2485-2492.1992.
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 Klebsiella 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.
产气克雷伯菌的maoA基因参与单胺氧化酶的合成，可被酪胺及相关化合物诱导，受分解代谢物和铵离子阻遏，并被克隆。测定了参与单胺氧化酶合成区域的核苷酸序列。发现了两个开放阅读框，即maoA基因和一个此前未知的基因（maoC）。它们位于一个潜在的启动子序列和一个转录终止子序列之间。发现大肠杆菌染色体上有一个区域与克雷伯菌的maoA基因高度同源。潜在的maoA基因位于大肠杆菌染色体的30.9分钟处。对纯化的单胺氧化酶N端前11个氨基酸的氨基酸序列分析与从maoA基因核苷酸序列推导的结果一致。前导肽延伸超过30个氨基酸，具有信号序列的特征。体内产生的转录本的引物延伸和S1核酸酶图谱分析表明，酪胺诱导的mRNA起始于maoC基因ATG起始密码子上游62个碱基处。在假定的启动子区域，发现与环腺苷酸受体蛋白结合位点的共有序列高度相似。因此，mao区域由两个顺反子组成，mao操纵子受单胺化合物、葡萄糖和铵离子调控。
