View source for 8tm3


==Human proteasome alpha ring assembly intermediate==
<StructureSection load='8tm3' size='340' side='right'caption='[[8tm3]], [[Resolution|resolution]] 3.00&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[8tm3]] is a 10 chain structure with sequence from [https://en.wikipedia.org/wiki/Homo_sapiens Homo sapiens]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=8TM3 OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=8TM3 FirstGlance]. <br>
</td></tr><tr id='method'><td class="sblockLbl"><b>[[Empirical_models|Method:]]</b></td><td class="sblockDat" id="methodDat">Electron Microscopy, [[Resolution|Resolution]] 3&#8491;</td></tr>
<tr id='resources'><td class="sblockLbl"><b>Resources:</b></td><td class="sblockDat"><span class='plainlinks'>[https://proteopedia.org/fgij/fg.htm?mol=8tm3 FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=8tm3 OCA], [https://pdbe.org/8tm3 PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=8tm3 RCSB], [https://www.ebi.ac.uk/pdbsum/8tm3 PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=8tm3 ProSAT]</span></td></tr>
</table>
== Function ==
[https://www.uniprot.org/uniprot/PSA2_HUMAN PSA2_HUMAN] The proteasome is a multicatalytic proteinase complex which 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. The proteasome has an ATP-dependent proteolytic activity. PSMA2 may have a potential regulatory effect on another component(s) of the proteasome complex through tyrosine phosphorylation.
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== Publication Abstract from PubMed ==
New proteasomes are produced to accommodate increases in cellular catabolic demand and prevent the accumulation of cytotoxic proteins. Formation of the proteasomal 20S core complex relies on the function of the five chaperones PAC1-4 and POMP. Here, to understand how these chaperones facilitate proteasome assembly, we tagged the endogenous chaperones using CRISPR/Cas gene editing and examined the chaperone-bound complexes by cryo-EM. We observe an early alpha-ring intermediate subcomplex that is stabilized by PAC1-4, which transitions to beta-ring assembly upon dissociation of PAC3/PAC4 and rearrangement of the PAC1 N-terminal tail. Completion of the beta-ring and dimerization of half-proteasomes repositions critical lysine K33 to trigger cleavage of the beta pro-peptides, leading to the concerted dissociation of POMP and PAC1/PAC2 to yield mature 20S proteasomes. This study reveals structural insights into critical points along the assembly pathway of the human proteasome and provides a molecular blueprint for 20S biogenesis.

Structural basis of human 20S proteasome biogenesis.,Zhang H, Zhou C, Mohammad Z, Zhao J Nat Commun. 2024 Sep 18;15(1):8184. doi: 10.1038/s41467-024-52513-0. PMID:39294158<ref>PMID:39294158</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
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<div class="pdbe-citations 8tm3" style="background-color:#fffaf0;"></div>
== References ==
<references/>
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</StructureSection>
[[Category: Homo sapiens]]
[[Category: Large Structures]]
[[Category: Zhang H]]
[[Category: Zhao J]]