Probable substrate-recognition component of a SCF-like ECS (Elongin-Cullin-SOCS-box protein) E3 ubiquitin-protein ligase complex which mediates the ubiquitination and subsequent proteasomal degradation of target proteins. Protein modification; protein ubiquitination. Interacts with CUL5 and RNF7. The SOCS box domain mediates the interaction with the Elongin BC complex, an adapter module in different E3 ubiquitin-protein ligase complexes. Belongs to the ankyrin SOCS box (ASB) family.