(a) SCF contains three core subunits—the RING protein Rbx1, the cullin Cul1, and Skp1. Rbx1 binds the E2–ubiquitin conjugate. The target protein binds to an F-box protein that is bound to the enzyme core via interactions with the Skp1 subunit. After binding of a target protein to the F-box protein, the ubiquitin is transferred from E2 and attached via a peptide bond to a lysine side chain in the target protein. (b) A composite model structure for human SCF derived from X-ray structures of human Rbx1–Cul1–Skp1–Skp2 complex and the E2 enzyme Ubc7. The target protein (not shown here) interacts with the F-box protein Skp2, which thereby positions the substrate for ubiquitination by the E2 enzyme. Ubiquitin is not shown in this model but at the start of the reaction it would be bound to the E2 enzyme at the active-site cysteine shown in blue. (Adapted from Zheng, N. et al.: Nature 2002, 416:703–709.) (PDB 1fbv, 1ldk, 1fqr)
Skp, Cullin, F-box containing complex (or SCF complex ) is a multi-protein E3 ubiquitin ligase complex that catalyzes the ubiquitination of proteins destined for 26S proteasomal degradation.[ 1] Along with the anaphase-promoting complex ,[ 2] SCF has important roles in the ubiquitination of proteins involved in the cell cycle. The SCF complex also marks various other cellular proteins for destruction.[ 3]
^ Ou, Young; Rattner, J.B. (2004), "The Centrosome in Higher Organisms: Structure, Composition, and Duplication", International Review of Cytology , 238 , Elsevier: 119–182, doi :10.1016/s0074-7696(04)38003-4 , ISBN 978-0-12-364642-2 , PMID 15364198
^ Fischer, Martin; Dang, Chi V.; DeCaprio, James A. (2018), "Control of Cell Division", Hematology , Elsevier, pp. 176–185, doi :10.1016/b978-0-323-35762-3.00017-2 , ISBN 978-0-323-35762-3
^ Morgan, David "Protein Degradation in Cell-Cycle Control", The Cell Cycle; Principles of Control 2007