Substrate-recognition component of the DCX(DCAF15) complex, a cullin-4-RING E3 ubiquitin-protein ligase complex that mediates ubiquitination and degradation of target proteins. The DCX(DCAF15) complex acts as a regulator of the natural killer (NK) cells effector functions, possibly by mediating ubiquitination and degradation of cohesin subunits SMC1A and SMC3. May play a role in the activation of antigen-presenting cells (APC) and their interaction with NK cells. Protein modification; protein ubiquitination. Component of the DCX(DCAF15) complex, also named CLR4(DCAF15) complex, composed of DCAF15, DDB1, cullin-4 (CUL4A or CUL4B), DDA1 and RBX1.