Essential component of the SCF (SKP1-CUL1-F-box protein) E3 ubiquitin ligase complexes, which mediate the ubiquitination and subsequent proteasomal degradation of target proteins (By similarity). Controls sulfur metabolite repression, probably by mediating the inactivation or degradation of the metR transcription factor. Protein modification; protein ubiquitination. Component of the SCF (SKP1-CUL1-F-box protein) E3 ubiquitin ligase complexes. Belongs to the SKP1 family.