| Structural highlights
Function
FBX2_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 PubMed
The 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.
See Also
References
- ↑ Yoshida Y, Chiba T, Tokunaga F, Kawasaki H, Iwai K, Suzuki T, Ito Y, Matsuoka K, Yoshida M, Tanaka K, Tai T. E3 ubiquitin ligase that recognizes sugar chains. Nature. 2002 Jul 25;418(6896):438-42. PMID:12140560 doi:10.1038/nature00890
- ↑ Yoshida Y, Adachi E, Fukiya K, Iwai K, Tanaka K. Glycoprotein-specific ubiquitin ligases recognize N-glycans in unfolded substrates. EMBO Rep. 2005 Mar;6(3):239-44. PMID:15723043 doi:http://dx.doi.org/10.1038/sj.embor.7400351
- ↑ Yamaguchi Y, Hirao T, Sakata E, Kamiya Y, Kurimoto E, Yoshida Y, Suzuki T, Tanaka K, Kato K. Fbs1 protects the malfolded glycoproteins from the attack of peptide:N-glycanase. Biochem Biophys Res Commun. 2007 Oct 26;362(3):712-6. Epub 2007 Aug 20. PMID:17720138 doi:http://dx.doi.org/10.1016/j.bbrc.2007.08.056
- ↑ Yoshida Y, Murakami A, Iwai K, Tanaka K. A neural-specific F-box protein Fbs1 functions as a chaperone suppressing glycoprotein aggregation. J Biol Chem. 2007 Mar 9;282(10):7137-44. Epub 2007 Jan 10. PMID:17215248 doi:http://dx.doi.org/10.1074/jbc.M611168200
- ↑ Mizushima T, Hirao T, Yoshida Y, Lee SJ, Chiba T, Iwai K, Yamaguchi Y, Kato K, Tsukihara T, Tanaka K. Structural basis of sugar-recognizing ubiquitin ligase. Nat Struct Mol Biol. 2004 Apr;11(4):365-70. Epub 2004 Feb 29. PMID:14990996 doi:http://dx.doi.org/10.1038/nsmb732
- ↑ Mizushima T, Yoshida Y, Kumanomidou T, Hasegawa Y, Suzuki A, Yamane T, Tanaka K. Structural basis for the selection of glycosylated substrates by SCF(Fbs1) ubiquitin ligase. Proc Natl Acad Sci U S A. 2007 Apr 3;104(14):5777-81. Epub 2007 Mar 26. PMID:17389369
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