CHARACTERIZATION OF VACCINIA VIRUS GENE-B12R

We report the characterization or vaccinia virus gene B12R which is pr edicted to encode a 33K protein with 36% amino acid identity to the se rine/threonine protein kinase encoded by vaccinia virus gene B1R. S1 n uclease protection experiments showed that gene B12R is transcribed ea rly during infection from an initiation site 11 bp upstream of the ope n reading frame (ORF). The gene encodes a 33K polypeptide that is not required for virus replication in tissue culture nor for virus virulen ce in a murine intranasal model. Expression of the B12R gene in Escher ichia coli produced an abundant 33K polypeptide which lacked protein k inase activity under conditions in which the protein kinases encoded b y vaccinia virus gene B1R and African swine fever virus gene j9L are a ctive.