Substrate-recognition component of a Cul2-RING (CRL2) E3 ubiquitin-protein ligase complex, which mediates ubiquitination of target proteins, leading to their degradation (PubMed:26138980). The CRL2(PRAMEF9) complex mediates ubiquitination and degradation of truncated MSRB1/SEPX1 selenoproteins produced by failed UGA/Sec decoding (PubMed:26138980). Protein modification; protein ubiquitination. Component of a CRL2 E3 ubiquitin-protein ligase complex, also named ECS (Elongin BC-CUL2/5-SOCS-box protein) complex, composed of CUL2, Elongin BC (ELOB and ELOC), RBX1 and substrate-specific adapter PRAMEF9. Belongs to the PRAME family.