高产S-腺苷蛋氨酸合成酶基因工程菌的构建

Construction of high-yield S-adenosyl-L-methionine synthetase using a genetic engineered strain

应用PCR技术,以大肠杆菌BL21(DE3)染色体DNA为模板,扩增得到S-腺苷蛋氨酸(SAM)合成酶基因。将所得基因连接至表达载体pET-22b(+),利用T7强启动子进行转录,然后转化进E.coli BL21(DE3)表达菌株,构建出了具有高效表达SAM合成酶基因的基因工程菌。重组菌所表达的酶活为115 U/g(以细胞干重计)。

The polymerase chain reaction （PCR） technique has been employed to amplify the S-adenosyl-L-methio- nine synthetase （SAMS） gene using the genomic DNA from E. coli BL21 as the template. The gene was cloned in- to the expression vector pET-22b （ ＋ ） under the control of the strong T7-promoter. The recombinant vector was transformed into the E. coli BL21 （DE3）strain to construct the genetic engineered strain for producing high-yield SAMS. The measured enzyme activity was 115 U/g.