Component of the SCF (SKP1-CUL1-F-box protein) E3 ubiquitin ligase complex, which mediates the ubiquitination and subsequent proteasomal degradation of target proteins. Through the RING-type zinc finger, seems to recruit the E2 ubiquitination enzyme to the complex and brings it into close proximity to the substrate (By similarity). Protein modification; protein ubiquitination. Part of a SCF complex consisting of Skpa (SKP1), Cul1, Roc1B and a F-box protein. Highly expressed in early embryos, and in pupae. Widely expressed in adult males, while it is weakly expressed in adult females. The RING-type zinc finger domain is essential for ubiquitin ligase activity. It coordinates an additional third zinc ion (By similarity). Belongs to the RING-box family. It is uncertain whether Met-1 or Met-16 is the initiator.