J. Biol. Chem., Vol. 261, Issue 18, 8283-8289, 06, 1986
Purification and characterization of a protein synthesis inhibitor associated with vaccinia virus
A Person-Fernandez and G Beaud
A protein synthesis inhibitor, solubilized from vaccinia virus (Ben-
Hamida, F., Person, A., and Beaud, G. (1983) J. Virol. 45, 452-455), has
been purified to homogeneity, yielding a basic protein with molecular mass
of 11 kDa. This purified protein migrates as a single spot in
two-dimensional gel analysis (isoelectric point above 8.6). It is
phosphorylated by the vaccinia-associated protein kinase, and it aggregates
in the absence of reducing agents. This 11-kDa protein inhibits protein
synthesis when added to a reticulocyte lysate at a stoichiometric ratio of
approximately one protein molecule/ribosome, and it associates with the
ribosome fraction after incubation in reticulocyte lysates or in Ehrlich
ascites tumor cell lysates. As previously described for the inhibitor
associated with vaccinia cores, the purified inhibitor inhibits the
formation of the 40 S ribosomal subunit X Met-tRNAi ribosomal initiation
complex. It has no detectable effect on the formation of the ternary
complex (Met-tRNAi X GTP X eucaryotic initiation factor 2). This inhibitor
associated with vaccinia virus particles may be involved in the shutoff of
host protein synthesis and may also be responsible for the absence of virus
replication in some cell-virus systems.