2005 年 47 巻 3 号 p. 197-203
SCFFbsl is a ubiquitin-ligase that plays a role in the endoplasmic reticulum-associated degradation pathway. Fbsl/Fbx2, a member of the F-box proteins, recognizes high-mannose oligosaccharides. The structure of the sugar-binding domain-chitobiose complex includes hydrogen bonds between Fbs1 and chitobiose and insertion of the methyl-group of chitobiose into a small hydrophobic pocket of Fbsl. We propose that Fbsl interacts with the chitobiose in unfolded N-glycoproteins, pointing the protein moiety toward E2 for ubiquitination.