Probable substrate recognition component of an ECS (Elongin BC-CUL2/5-SOCS-box protein) E3 ubiquitin ligase complex which mediates the ubiquitination and subsequent proteasomal degradation of target proteins. Protein modification; protein ubiquitination. Part of an E3 ubiquitin-protein ligase complex with Elongin BC (ELOB and ELOC), RBX1 and CUL5. Component of a probable ECS(LRRC41) complex which contains CUL5, RNF7/RBX2, Elongin BC and LRRC41. Interacts with CUL5, RNF7, ELOB and ELOC (By similarity). The Elongin BC complex binding domain is also known as BC-box with the consensus [APST]-L-x(3)-C-x(3)-[AILV]. It is uncertain whether Met-1 or Met-23 is the initiator.