abstract |
The invention provides a process for producing PNPase, wherein PNPase can be produced easily with high efficiency, and problematic contamination with endotoxin in synthesis of a nucleic acid polymer as a raw material of pharmaceutical preparations can be reduced. PNPase is produced by Escherichia coil or the like having a T7 RNA polymerase gene, transformed with an expression vector having a PNPase gene and a T7 promoter ligated therein. For further facilitating the step of purifying PNPase, an expression vector having a tag gene is utilized and the culture time is prolonged. |