– Plays a role in the dissolution of the outermost membrane of extracellular enveloped virions (EEV) to allow virion entry into host cells. Participates also in wrapping intracellular mature virions (IMV) to form intracellular enveloped virions (IEV). Vaccinia virus (strain Copenhagen) OPG190 Protein (His) is expressed in yeast with N-6xHis tag. The predicted molecular weight is 31.1 kDa and the accession number is P21115.