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Crystal Structure of the Yeast 20S Proteasome in Complex with Homobelactosin CCrystal Structure of the Yeast 20S Proteasome in Complex with Homobelactosin C
Structural highlights
FunctionPSA2_YEAST The proteasome degrades poly-ubiquitinated proteins in the cytoplasm and in the nucleus. It is essential for the regulated turnover of proteins and for the removal of misfolded proteins. The proteasome is a multicatalytic proteinase complex that is characterized by its ability to cleave peptides with Arg, Phe, Tyr, Leu, and Glu adjacent to the leaving group at neutral or slightly basic pH. It has an ATP-dependent proteolytic activity. Evolutionary ConservationCheck, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf. Publication Abstract from PubMedMost class I MHC ligands are generated from the vast majority of cellular proteins by proteolysis within the ubiquitin-proteasome pathway and are presented on the cell surface by MHC class I molecules. Here, we present the crystallographic analysis of yeast 20S proteasome in complex with the inhibitor homobelactosin C. The structure reveals a unique inhibitor-binding mode and provides information about the composition of proteasomal primed substrate-binding sites. IFN-gamma inducible substitution of proteasomal constitutive subunits by immunosubunits modulates characteristics of generated peptides, thus producing fragments with higher preference for binding to MHC class I molecules. The structural data for the proteasome:homobelactosin C complex provide an explanation for involvement of immunosubunits in antigen generation and open perspectives for rational design of ligands, inhibiting exclusively constitutive proteasomes or immunoproteasomes. Inhibitor-binding mode of homobelactosin C to proteasomes: new insights into class I MHC ligand generation.,Groll M, Larionov OV, Huber R, de Meijere A Proc Natl Acad Sci U S A. 2006 Mar 21;103(12):4576-9. Epub 2006 Mar 13. PMID:16537370[1] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See AlsoReferences |
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