Terminase large subunit (TerL) from bacteriophages and evolutionarily related viruses, is an important component of the DNA packing machinery and comprises an ATPase domain, which powers DNA translocation and a nuclease domain that cuts concatemeric DNA [1,2]. TerL forms pentamers in which the ATPase domains form a ring distal to the capsid. This is the ATPase domain which contains a C-terminal subdomain that sits above the ATPase active site, called the "Lid subdomain" with reference to analogous lid subdomains found in other ATPases [3]. It contains a hydrophobic patch (Trp and Tyr residues) that mediates critical interactions in the interface between adjacent ATPase subunits and assists the positioning of the arginine finger residue that catalyses ATP hydrolysis [2,3]. This entry also includes bacterial proteins of unknown function.

1: Sequence and organization of the lactococcal prolate-headed bIL67 phage genome. Schouler C, Ehrlich SD, Chopin MC; Microbiology 1994;140:3061-3069. PMID:7812447

2: Viral genome packaging terminase cleaves DNA using the canonical RuvC-like two-metal catalysis mechanism. Xu RG, Jenkins HT, Chechik M, Blagova EV, Lopatina A, Klimuk E, Minakhin L, Severinov K, Greive SJ, Antson AA; Nucleic Acids Res. 2017;45:3580-3590. PMID:28100693

3: Structure and mechanism of the ATPase that powers viral genome packaging. Hilbert BJ, Hayes JA, Stone NP, Duffy CM, Sankaran B, Kelch BA; Proc Natl Acad Sci U S A. 2015;112:E3792-E3799. PMID:26150523