F-box domain found in F-box only proteins FBXO6, FBXO44 and similar proteins
This subfamily includes FBXO6 and FBXO44. FBXO6, also called FBX6, F-box protein that recognizes sugar chains 2 (FBS2), or F-box/G-domain protein 2 (FBG2), is a substrate-recognition component of SCF (SKP1-CUL1-F-box protein)-type E3 ubiquitin ligase complexes. It is involved in the endoplasmic reticulum-associated degradation pathway (ERAD) for misfolded lumenal proteins, by recognizing and binding sugar chains on unfolded glycoproteins that are retro-translocated into the cytosol and promoting their ubiquitination and subsequent degradation. FBXO6 can recognize and bind denatured glycoproteins, which are modified with not only high-mannose but also complex-type oligosaccharides. It also recognizes sulfated glycans. FBXO6 is involved in DNA damage response by specifically recognizing activated CHEK1 (phosphorylated on 'Ser-345'), promoting its ubiquitination and degradation. FBXO44, also called FBXO6A, FBX44, or F-box/G-domain protein 3 (FBG3), is a substrate-recognition component of an SCF-type E3 ubiquitin ligase complex. It interacts with SKP1 and CUL1. FBXO44 mediates BRCA1 ubiquitination and degradation. 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:
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.
Structure:3WSO; Homo sapiens FBXO44 in complex with Skp1, contacts at 4A
Jiyao W et al.(2023). "The conserved domain database in 2023.",