3gpj
Crystal structure of the yeast 20S proteasome in complex with syringolin B
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 Conservation Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf. Publication Abstract from PubMedSyrbactins, a family of natural products belonging either to the syringolin or glidobactin class, are highly potent proteasome inhibitors. Although sharing similar structural features, they differ in their macrocyclic lactam core structure and exocyclic side chain. These structural variations critically influence inhibitory potency and proteasome subsite selectivity. Here, we describe the total synthesis of syringolin A and B, which together with enzyme kinetic and structural studies, allowed us to elucidate the structural determinants underlying the proteasomal subsite selectivity and binding affinity of syrbactins. These findings were used successfully in the rational design and synthesis of a syringolin A-based lipophilic derivative, which proved to be the most potent syrbactin-based proteasome inhibitor described so far. With a K(i)' of 8.65 +/- 1.13 nM for the chymotryptic activity, this syringolin A derivative displays a 100-fold higher potency than the parent compound syringolin A. In light of the medicinal relevance of proteasome inhibitors as anticancer compounds, the present findings may assist in the rational design and development of syrbactin-based chemotherapeutics. Synthetic and structural studies on syringolin A and B reveal critical determinants of selectivity and potency of proteasome inhibition.,Clerc J, Groll M, Illich DJ, Bachmann AS, Huber R, Schellenberg B, Dudler R, Kaiser M Proc Natl Acad Sci U S A. 2009 Apr 21;106(16):6507-12. Epub 2009 Apr 9. PMID:19359491[1] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See AlsoReferences
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