CMV belongs to the Beta herpes virinae subfamily of Herpes viridae which includes herpes simplex virus types 1 and 2, varicella-zoster virus, and Epstein-Barr virus. The herpes viruses share a characteristic ability to remain latentover long periods.CMV is a double-stranded linear DNA virus with 162 hexagonal protein capsomeres surrounded by a lipid membrane. CMV has the largest genome of the herpes viruses, ranging from 230-240 kilobase pairs. Human CMV is composed of unique and inverted repeats that include the existence of 4 genome isomers caused by inversion of L-S genome components (class E). Replication may be divided into immediate early, delayed early, and late gene expression based on time of synthesis after infection. The DNA is replicated by rolling circles. In vitro, CMV replicates in human fibroblasts. Alternative Names: UL83 protein, CMV Pp 65 protein, Cytomegalovirus pp65 Tegument Protein (UL83), CMV pp65 UL83 protein, CMV Pp-65 protein, Cytomegalovirus Pp65 protein, CMV Pp-65, CMV Pp 65, CMV Pp65