Nsp10 have shown that it is a 15-kDa protein of unknown function that has been shown to interact with itself, nsp1, and nsp7. It colocalizes with N to sites of viral replication and is essential for replication. It plays a pivotal role in viral transcription by stimulating both nsp14 3'-5' exoribonuclease and nsp16 2'-O-methyltransferase activities. Therefore plays an essential role in viral mRNAs cap methylation. Nsp10 is a critical regulator of coronavirus RNA synthesis and may play an important role in polyprotein processing.