The NTD domain (amino acids range 60-194) and SR-rich region (amino acids range 195-230) are known as they play an important role in CoV, both in viral replication and transcription. For example; NMR  chemical shift perturbation studies reveal that the regions of the SR-rich and NTD in MHV N protein interact with MHV nsp3. They, which are N and nsp3 proteins, also mapped  basic determinants of this high affinity binding to the SR region of N and acidic α2 helix of NSP3.