Human cytomegalovirus DNA terminase complex (CMV DNA terminase complex)

The **Human cytomegalovirus DNA terminase complex** is an essential multi-subunit viral enzyme complex required for the maturation and packaging of viral genomes during cytomegalovirus (HCMV) replication[1][2][3][6][7]. The core functional complex consists mainly of the large subunit pUL56, which possesses ATPase activity, and the small subunit pUL89, with nuclease activity[1][2][4][7]. These proteins cooperate to recognize concatemeric viral DNA, cleave it into unit-length genomes, and translocate the cleaved genome into preformed capsids, a process essential for infectious virion production[3][5][6]. Additional viral proteins such as pUL51, pUL52, pUL77, and pUL93 may also participate in terminase complex assembly and activity[3][6]. The **terminase complex** is a validated drug target, as inhibitors such as Letermovir can block viral replication by preventing the cleavage and encapsidation of viral DNA[5][9]. This mechanism is distinct from currently available nucleoside analog antivirals, offering a novel approach to the treatment of CMV infection, particularly in immunocompromised patients where the virus poses serious health risks[5][9]. Resistance can develop through mutations in the genes encoding the terminase complex. The complex and its subunits are highly conserved among herpesviruses and function analogously to similar DNA packaging motors found in dsDNA bacteriophages[3][8]. No evidence indicates a misspelling or conceptual error in the submitted target name; this target refers to a specific and therapeutically relevant viral protein complex.

Other names

HCMV terminase complexHerpesvirus terminase complexUL89/UL56 complexHuman cytomegalovirus terminase

Inhibition of DNA cleavage/packaging; Inhibition of ATPase activity required for genome translocation; Blockage of nuclease activity needed to process concatemeric viral DNA