Fujita M, Futai M, Amemura A
Department of Biotechnology, Faculty of Engineering, Fukuyama University, Japan.
J Bacteriol. 1990 Mar;172(3):1595-9. doi: 10.1128/jb.172.3.1595-1599.1990.
Northern hybridization and S1 nuclease mapping revealed that the amyP gene coding for maltotetraose-forming amylase of Pseudomonas stutzeri MO-19 is transcribed as a monocistronic mRNA of 2.0 kilobases and that the transcription start site is located 81 base pairs upstream from the first nucleotide of the initiation codon. The amyP gene was expressed weakly in Escherichia coli, and transcription started 49 base pairs downstream of the P. stutzeri MO-19 transcription start site. Synthesis of the amylase in P. stutzeri MO-19 was induced by the addition of maltose to the culture medium and was repressed by the addition of glucose. The induction by maltose was shown to be result of transcription induction of the amyP gene. In contrast, glucose did not repress transcription initiation of amyP, indicating that it controls synthesis of the enzyme, probably at the posttranscriptional level.
Northern杂交和S1核酸酶图谱分析表明，编码施氏假单胞菌MO-19麦芽四糖生成淀粉酶的amyP基因转录为一条2.0千碱基的单顺反子mRNA，转录起始位点位于起始密码子第一个核苷酸上游81个碱基对处。amyP基因在大肠杆菌中表达较弱，转录起始于施氏假单胞菌MO-19转录起始位点下游49个碱基对处。在施氏假单胞菌MO-19中，向培养基中添加麦芽糖可诱导淀粉酶的合成，而添加葡萄糖则可抑制其合成。麦芽糖诱导是amyP基因转录诱导的结果。相比之下，葡萄糖并不抑制amyP的转录起始，这表明它可能在转录后水平控制该酶的合成。
