Capsid Protein VP4 of Poliovirus in N-myristoylated

Poliovirus was labeled in vivo with [3H]myristic acid. Analysis of the capsid polypeptides revealed that the [3H]myristic acid residues copurified with VP4, the smallest and internal capsid protein of the virion. Evidence is presented showing unambiguously that the N-terminal glycine residue of VP4 is N-myristoylated. A previous analysis of the tryptic peptides of VP4 [Dorner, A. J., Dorner, L. F., Larsen, G. R., Wimmer, E. & Anderson, C. W. (1982) J. Virol. 42, 1017-1028] had shown that the N-terminal blocking group exists on all VP4 molecules as well as on VP0 and P1, two precursor polypeptides to VP4 in poliovirus. The possible function of the myristic acid residue in VP4 and in its precursor in poliovirus proliferation is discussed.