cl19377

Phage terminase large subunit (GpA); 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, gpA, products of the Nu1 and A genes, respectively. Terminase is involved in the site-specific binding and cutting of the DNA in the initial stages of packaging. It is now known that gpA is actively involved in late stages of packaging, including DNA translocation, and that this enzyme contains separate functional domains for its early and late packaging activities.