This family of proteins, functionally uncharacterised, is found in bacteria and viruses. Proteins in this family are typically between 341 and 365 amino acids in length. Some members are thought to be coat proteins.

1: Structure of the Marine Siphovirus TW1: Evolution of Capsid-Stabilizing Proteins and Tail Spikes. Wang Z, Hardies SC, Fokine A, Klose T, Jiang W, Cho BC, Rossmann MG; Structure. 2018;26:238-248. PMID:29290487