The coding region of cdna was cloned into procaryotic expression vector pet30a and overexpressed in e . coli bl21 ( de3 ) . the cyclase proteins extracted from bacterial culture were found largely in the insoluble protein fraction Cdna编码区序列被克隆进原核表达载体pet - 30a ，并在大肠杆菌bl21 ( de3 )中诱导表达，但过量表达的蛋白主要是以不溶性蛋白形式存在。
