This family represents the N-terminal domain of the RING finger protein 37 (RNF37), an U-box domain-containing protein. This is a variable region that probably has a role in function regulation [1].

1: Structural and functional characterization of the monomeric U-box domain from E4B. Nordquist KA, Dimitrova YN, Brzovic PS, Ridenour WB, Munro KA, Soss SE, Caprioli RM, Klevit RE, Chazin WJ; Biochemistry. 2010;49:347-355. PMID:20017557