Palmitylation of the vaccinia virus 37-kDa major envelope antigen. Identification of a conserved acceptor motif and biological relevance.

Computer-assisted alignment of known palmitylproteins was used to identify a potential peptide motif, TMDX1-12AAC(C)A (TMD, transmembrane domain; X, any amino acid; C, cysteine acceptor residues; A, aliphatic residue) responsible for directing internal palmitylation of the vaccinia virus 37-kDa major envelope antigen, p37. Site-directed mutagenesis was used to confirm this motif as the site of modification and to produce a nonpalmitylated version of the p37 protein. Comparative phenotypic analysis of the wild-type and mutant p37 alleles confirmed that the p37 protein is involved in viral envelopment and egress, and suggested that attachment of the palmitate moiety was essential for correct intracellular targeting and protein function.