F-box domain found in F-box/LRR-repeat protein 3 (FBXL3), F-box/LRR-repeat protein 21 (FBXL21) and similar proteins
FBXL3, also called F-box and leucine-rich repeat protein 3A, or F-box/LRR-repeat protein 3A, is the substrate-recognition component of the SCF(FBXL3) E3 ubiquitin ligase complex that mainly acts in the nucleus and mediates ubiquitination and subsequent degradation of CRY1 and CRY2, and thus, is involved in circadian rhythm function. It plays a key role in the maintenance of both the speed and the robustness of the circadian clock oscillation. FBXL21, also called F-box and leucine-rich repeat protein 21, F-box and leucine-rich repeat protein 3B, or F-box/LRR-repeat protein 3B, is the substrate-recognition component of the SCF(FBXL21) E3 ubiquitin ligase complex that mainly acts in the cytosol and mediates ubiquitination of CRY proteins (CRY1 and CRY2), leading to CRY protein stabilization, and thus, is also involved in circadian rhythm function. It plays regulates the oscillation of the circadian clock through ubiquitination and stabilization of cryptochromes. The F-box domain has a role in mediating protein-protein interactions in a variety of contexts, such as polyubiquitination, transcription elongation, centromere binding and translational repression.
Feature 1:Skp1 binding site [polypeptide binding site]
Evidence:
Structure:4I6J; Homo sapiens FBXL3 in complex with Skp1, contacts at 4A
Comment:F-box proteins participate in SCF (Skp1-Cul1-F-box protein) complexes that function as ubiquitin E3 ligases, where the role of the F-box protein is to recruit target substrates.
Jiyao W et al.(2023). "The conserved domain database in 2023.",