Interacts with glycoprotein (gH). Both the 51 kDa and 49 kDa are present in the virion. Expressed late in the viral replication cycle. A long 51 kDa and a short 49 kDa protein are produced possibly by proteolytic cleavage. N-glycosylated with high-mannose and complex glycans. Belongs to the herpesviridae U47 family.