UC Irvine

Direct RNA sequence analysis of the E2 gene of wild-type MHV-4 and of neutralization resistant, neuroattenuated variants has identified a polymorphic region with respect to deletions. These variants had large deletions of 142 to 159 amino acids mapping to a localized region in the amino-terminal domain of the peplomer glycoprotein. The nucleotide sequence of the E2 gene for wild-type strain MHV-4 was found to be very similar to that of MHV-JHM but had an insertion of 423 nucleotides resulting in the addition of a stretch of 141 unique amino acids in the amino-terminal domain of E2. We propose that deletions reflect a major source of heterogeneity in the E2 protein of MHV.