This family consists of several phage terminase large subunit proteins as well as related sequences from several bacterial species. The DNA packaging enzyme of bacteriophage lambda, terminase, is a heteromultimer composed of a small subunit, gpNu1, and a large subunit, TerL (gpA), products of the Nu1 and A genes, respectively. Terminase is involved in the site-specific binding and cutting of the DNA during the DNA packaging process. TerL contains all the catalytic activities required for for DNA maturation and packaging. At the N-terminal (represented in this entry) reside the DNA translocase (packaging) and ATPase activities, while at the C-terminal resides the DNA maturation (nuclease/helicase) catalytic activity [1,2,3,4].

1: The large subunit of bacteriophage lambda's terminase plays a role in DNA translocation and packaging termination. Duffy C, Feiss M; J Mol Biol 2002;316:547-561. PMID:11866517

2: The enzymology of a viral genome packaging motor is influenced by the assembly state of the motor subunits. Andrews BT, Catalano CE; Biochemistry. 2012;51:9342-9353. PMID:23134123

3: Evidence that a catalytic glutamate and an 'Arginine Toggle' act in concert to mediate ATP hydrolysis and mechanochemical coupling in a viral DNA packaging motor. Ortiz D, delToro D, Ordyan M, Pajak J, Sippy J, Catala A, Oh CS, Vu A, Arya G, Feiss M, Smith DE, Catalano CE; Nucleic Acids Res. 2019;47:1404-1415. PMID:30541105

4: The DNA maturation domain of gpA, the DNA packaging motor protein of bacteriophage lambda, contains an ATPase site associated with endonuclease activity. Ortega ME, Gaussier H, Catalano CE; J Mol Biol. 2007;373:851-865. PMID:17870092