The murine cytomegalovirus M73.5 gene, a member of a 3' co-terminal alternatively spliced gene family, encodes the gp24 virion glycoprotein.

Abstract We have identified a novel family of five 3′ co-terminal transcripts in murine cytomegalovirus (MCMV) arranged in a tail-to-tail orientation with respect to the MCMV glycoprotein H (gH) gene M75 . They share the same exon 2 sequence but possess different exon 1 sequences. Two of these spliced transcripts ( M73 ) encode the MCMV homolog of glycoprotein N (gN) entirely within exon 1. Two other transcripts designated M73.5 encode a previously described virion glycoprotein gp24 that shares its first 20 amino acids with gN, but which has another 64 amino acids encoded within exon 2. The fifth transcript, designated m60 , has an 80-bp exon 1 near the MCMV oriLyt region 10.8 kb upstream of exon 2. Both MCMV M73.5 and m60 encode type II glycoproteins expressed at the cell surface. Their shared exon 2 coding sequences likely represent the highly conserved region of an as yet unidentified betaherpesvirus-specific glycoprotein species.