Abstract: With the rapid development of RNA related studies, RNA synthesis technology is further challenged from two aspects of quality and quantity. At present there are mainly two methods for RNA synthesis, chemical synthesis and enzymatic synthesis. By the commercialized chemical way, the synthesis of RNA with < 90 bases is achieved；however, the cost of the synthesis is relatively high, which leads the initiation of many researches in difficulty. Compared to the chemical way, the enzymatic synthesis presents the characteristics of the high efficiency and mild reaction conditions, and by it a long sequence of RNA can be synthesized, thus, it is an efficient and low-cost measure for RNA synthesis. The enzymatic production of RNA is in two steps, transcription and processing of initial transcripts. The transcription may be further classified into the linear transcription and the rolling circle transcription model, with which the characteristics of initial transcripts vary, and the corresponding processing methods should adapted to the varied initial transcripts, thereby, the accurate target RNA products may be obtained. Recently, as the exploration of enzymatic synthesis continues, many novel transcription and processing strategies have been developed. In this review, the mechanisms, characteristics and problems of the transcription models and processing methods in enzymatic synthesis were summarized, aiming at providing the references for further study and selective utilization of enzymatic synthesis of RNA.

Key words: RNA, enzymatic synthesis, linear transcription, rolling circle transcription, site-specific cleavage