A thermophilic phage uses a small terminase protein with a fixed helix-turn-helix geometry.
Hayes JA, Hilbert BJ, Gaubitz C, Stone NP, Kelch BA. A thermophilic phage uses a small terminase protein with a fixed helix-turn-helix geometry. J Biol Chem. 2020 03 20; 295(12):3783-3793.