May act as a substrate recognition component of an ECS (Elongin BC-CUL5-SOCS-box protein) E3 ubiquitin ligase complex which mediates the ubiquitination and subsequent proteasomal degradation of target proteins. May bind to the methyltransferase cofactor S-adenosylmethionine (AdoMet) via the N-terminal AdoMet binding motif, but probably does not display methyltransferase activity.