SUMMARY POINTS:

• Coronavirus cis-acting RNA elements involved in RNA synthesis are mainly located in the highly structured 5′ and 3’UTRs
• The replicase proteins nsp7, nsp8, nsp12, and nsp14 may constitute an RTC core complex
• Coronaviruses encode a proofreading machinery, unique among the RNA viruses, to ensure the maintenance of their large genome size. The ExoN activity of nsp14 is a key element of the proofreading system