Coronavirus replicase NSP9
Nsp9 is a single-stranded RNA-binding viral protein involved in RNA synthesis. Several crystallographic structures of nsp9 have shown that it is composed of seven beta strands and a single alpha helix. Nsp9 proteins have N-finger motifs and highly conserved GXXXG motifs that both play critical roles in dimerization. The conserved helix-helix dimer interface containing a GXXXG protein-protein interaction motif is biologically relevant to SARS-CoV replication.