Accessory subunit of the DNA polymerase that plays an essential role in viral DNA replication and acts by increasing the processivity of polymerization (PubMed:20538862, PubMed:20739543, PubMed:33967989). Forms dimers that binds to double-stranded DNA and UL54 specifically to stimulates long chain DNA synthesis efficiently. Plays an important role in maintaining the structure of viral replication compartments by interacting with host nucleolin/NUC (PubMed:22318319). In addition, suppresses innate immune responses through effects on host IRF3 and NF-kappa-B. Mechanistically, interfere with the binding of IRF3 and the p65 NF-kappa-B subunit to the promoters of antiviral genes, thereby inhibiting the expression of these genes (PubMed:30867312). Forms homodimers. Interacts with host SMARCB1. Interacts with host NCL/nucleolin; this interaction is important for the organization of proteins within viral replication compartments. Interacts with UL112/UL113; this interaction is necessary for efficient viral DNA replication. Interacts with UL84. Interacts with the uracil DNA glycosylase UL114. Interacts with the DNA polymerase catalytic subunit UL54. Interacts with host IRF3 (PubMed:30867312). Interacts with host RELA (PubMed:30867312). The C-terminal region is required for viral DNA synthesis. Phosphorylated by UL97 on serine residues, phosphorylation seems important for UL44 nuclear entry but does not directly affect its role in replication. Sumoylated. Sumoylation on Lys-410 increases viral DNA replication. Belongs to the herpesviridae polymerase accessory protein family.