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 iden tify a potential peptide motif, TMDX(1-12)AAC(C)A (TMD, transmembrane domain; X, any amino acid; C, cysteine acceptor residues; A, aliphatic residue) responsible for directing internal palmitylation of the vacc inia virus 37-kDa major envelope antigen, p37. Site-directed mutagenes is was used to confirm this motif as the site of modification and to p roduce a nonpalmitylated version of the p37 protein. Comparative pheno typic analysis of the wild-type and mutant p37 alleles confirmed that the p37 protein is involved in viral envelopment and egress, and sugge sted that attachment of the palmitate moiety was essential for correct intracellular targeting and protein function.