This is a family of uncharacterized proteins that fold into an alpha-beta-beta-beta-alpha fold and are structurally similar to HicB-like antitoxin. They are probably involved in RNA metabolism, RNA cleavage and binding [1].

1: Structure of a UPF0150-family protein from Thermus thermophilus HB8. Okazaki N, Kumei M, Manzoku M, Kuramitsu S, Shirouzu M, Shinkai A, Yokoyama S; Acta Crystallograph Sect F Struct Biol Cryst Commun. 2007;63:173-177. PMID:17329807