Phage terminase large subunit
Initiation of packaging of double-stranded viral DNA involves the specific interaction of the prohead with viral DNA in a process mediated by a phage-encoded terminase protein. The terminase enzymes are usually hetero-oligomers composed of a small and a large subunit. This region is found on the large subunit and possess an endonuclease and ATPase activity that require Mg2+ and a neutral or slightly basic reaction. This region is also found in bacterial sequences.
Jiyao W et al.(2023). "The conserved domain database in 2023.",