This entry represents the N-terminal domain of terminase large subunits found in a variety of the Caudovirales and prophage regions of bacterial genomes. It includes the terminase large subunit of Bacteriophage T4 (terminase gene 17, Gp17) [1,3]. Homologues are also found in Gene Transfer Agents (GTA) [2], including ORFg2 (RCAP_rcc01683) of the GTA of Rhodobacter capsulatus (Rhodopseudomonas capsulata) [see Fig.1, in 4].

1: Sequence analysis of bacteriophage T4 DNA packaging/terminase genes 16 and 17 reveals a common ATPase center in the large subunit of viral terminases. Mitchell MS, Matsuzaki S, Imai S, Rao VB; Nucleic Acids Res. 2002;30:4009-4021. PMID:12235385

2: The gene transfer agent of Rhodobacter capsulatus and "constitutive transduction" in prokaryotes. Lang AS, Beatty JT; Arch Microbiol. 2001;175:241-249. PMID:11382219

3: Isolation and characterization of T4 bacteriophage gp17 terminase, a large subunit multimer with enhanced ATPase activity. Baumann RG, Black LW; J Biol Chem. 2003;278:4618-4627. PMID:12466275

4: Evolutionary implications of phylogenetic analyses of the gene transfer agent (GTA) of Rhodobacter capsulatus. Lang AS, Taylor TA, Beatty JT; J Mol Evol. 2002;55:534-543. PMID:12399927