4rur
From Proteopedia
Yeast 20S proteasome in complex with the alkaloid indolo-phakellin (4)
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. Publication Abstract from PubMedThe proteasome represents an invaluable target for the treatment of cancer and autoimmune disorders. The application of proteasome inhibitors, however, remains limited to blood cancers because their reactive headgroups and peptidic scaffolds convey unfavorable pharmacodynamic properties. Thus, the discovery of more drug-like lead structures is indispensable. In this study, we present the first structure of the proteasome in complex with an indolo-phakellin that exhibits a unique noncovalent binding mode unparalleled by all hitherto reported inhibitors. The natural product inspired pentacyclic alkaloid binds solely and specificially into the spacious S3 subpocket of the proteasomal beta5 substrate binding channel, gaining major stabilization through halogen bonding with the protein backbone. The presented compound provides an ideal scaffold for the structure-based design of subunit-specific nonpeptidic proteasome-blockers. Indolo-Phakellins as beta5-Specific Noncovalent Proteasome Inhibitors.,Beck P, Lansdell TA, Hewlett NM, Tepe JJ, Groll M Angew Chem Int Ed Engl. 2015 Jan 7. doi: 10.1002/anie.201410168. PMID:25581903[1] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See AlsoReferences
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