2e32
Structural basis for selection of glycosylated substrate by SCFFbs1 ubiquitin ligase
Structural highlights
FunctionFBX2_MOUSE Substrate recognition component of a SCF (SKP1-CUL1-F-box protein) E3 ubiquitin-protein ligase complex that mediates the ubiquitination and subsequent proteasomal degradation of target proteins. Involved in the endoplasmic reticulum-associated degradation pathway (ERAD) for misfolded lumenal proteins by recognizing and binding sugar chains on unfolded glycoproteins that are retrotranslocated into the cytosol and promoting their ubiquitination and subsequent degradation. Prevents formation of cytosolic aggregates of unfolded glycoproteins that have been retrotranslocated into the cytosol. Able to recognize and bind denatured glycoproteins, preferentially those of the high-mannose type.[1] [2] [3] [4] [5] Evolutionary Conservation Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf. Publication Abstract from PubMedThe ubiquitin ligase complex SCF(Fbs1), which contributes to the ubiquitination of glycoproteins, is involved in the endoplasmic reticulum-associated degradation pathway. In SCF ubiquitin ligases, a diverse array of F-box proteins confers substrate specificity. Fbs1/Fbx2, a member of the F-box protein family, recognizes high-mannose oligosaccharides. To elucidate the structural basis of SCF(Fbs1) function, we determined the crystal structures of the Skp1-Fbs1 complex and the sugar-binding domain (SBD) of the Fbs1-glycoprotein complex. The mechanistic model indicated by the structures appears to be well conserved among the SCF ubiquitin ligases. The structure of the SBD-glycoprotein complex indicates that the SBD primarily recognizes Man(3)GlcNAc(2), thereby explaining the broad activity of the enzyme against various glycoproteins. Comparison of two crystal structures of the Skp1-Fbs1 complex revealed the relative motion of a linker segment between the F-box and the SBD domains, which might underlie the ability of the complex to recognize different acceptor lysine residues for ubiquitination. Structural basis for the selection of glycosylated substrates by SCF(Fbs1) ubiquitin ligase.,Mizushima T, Yoshida Y, Kumanomidou T, Hasegawa Y, Suzuki A, Yamane T, Tanaka K Proc Natl Acad Sci U S A. 2007 Apr 3;104(14):5777-81. Epub 2007 Mar 26. PMID:17389369[6] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. References
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