Fig. 1.

Deduced amino acid sequence of the polymerase motif region from open reading frame (ORF) 1b of the pol gene of 11 coronaviruses. The mouse hepatitis virus (MHV), infectious bronchitis virus (IBV) and 229E sequences are derived from published sequences (see text). The first amino acid in this figure corresponds to amino acid 466 of the IBV ORF 1b (Lee et al., 1991). Amino acids 79 through 307 correspond to 228 of the 258 amino acids representing the conserved polymerase motif common to coronaviruses, toroviruses and arteriviruses (see Fig. 5 in den Boon et al., 1991). The highly conserved SDD or GDD polymerase motif (Poch et al., 1989) is identified by asterisks. Capitalized letters indicate amino acids which are conserved in all 11 sequences.