Methods:Because of the overlapping gene between trpE and trpD,the trpED was cloned integrallty to produce a new high-expression vector pBV220-trpED.

• 由于trpE和trpD存在翻译偶联现象,将其自大肠杆菌基因组中经PCR扩增得到,构建新的表达质粒pBV220-trpED。