Core component of multiple cullin-RING-based ECS (ElonginB/C-CUL2/5-SOCS-box protein) E3 ubiquitin-protein ligase complexes, which mediate the ubiquitination of target proteins. May serve as a rigid scaffold in the complex and may contribute to catalysis through positioning of the substrate and the ubiquitin-conjugating enzyme. The E3 ubiquitin-protein ligase activity of the complex is dependent on the neddylation of the cullin subunit and is inhibited by the association of the deneddylated cullin subunit with TIP120A/CAND1 By similarity. The functional specificity of the ECS complex depends on the substrate recognition component. ECS(VHL) mediates the ubiquitination of hypoxia-inducible factor (HIF).Seiji Shiraishi, J. Biol. Chem., Mar 2007; 282: 9017 - 9028.Isabelle Groulx, J. Biol. Chem., Mar 2000; 275: 8991.Dimitris Liakopoulos, PNAS, May 1999; 96: 5510.Kyungwon Huh, AACR Meeting Abstracts, Apr 2006; 2006: 1326.