The replicase gene 1 products are encoded two very large open reading frames ORF1a and 1b, which are translated into two large polypeptides pp1a and pp1b, which are synthesized directly from the 5′ two-thirds of the genomic RNA of CoV. After synthesis of these proteins, consisting of 16 units, non-structural protein (nsp1 to nsp16) is converted with the contribution of viral proteases pp1a and pp1b. These 16 proteins form Double-Membran Vesicles (DMV). At the same time, this DMV is virus Replication and Transcription Complex (RTC). These nsp proteins, especially non-structural protein3 (nsp3), have an important role in the virion structure, the replication and transcription of CoV.