3jtl | pdb_00003jtl

Crystal structure of archaeal 20S proteasome in complex with mutated P26 activator

spinqualitylabelsall models 3jtl, resolution 3.20Å Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image   Print3D Structural highlights 3jtl is a 21 chain structure with sequence from Thermoplasma acidophilum and Trypanosoma brucei. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance. Related: 3jrm, 3jse Gene: psmA, Ta1288 (Thermoplasma acidophilum), psmB, Ta0612 (Thermoplasma acidophilum) Activity: Proteasome endopeptidase complex, with EC number 3.4.25.1 Resources: FirstGlance, OCA, RCSB, PDBsum 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 Proteasome activity is regulated by sequestration of its proteolytic centers in a barrel-shaped structure that limits substrate access. Substrates enter the proteasome by means of activator complexes that bind to the end rings of proteasome alpha subunits and induce opening of an axial entrance/exit pore. The PA26 activator binds in a pocket on the proteasome surface using main chain contacts of its C-terminal residues and uses an internal activation loop to trigger gate opening by repositioning the proteasome Pro-17 reverse turn. Subunits of the unrelated PAN/19S activators bind with their C termini in the same pockets but can induce proteasome gate opening entirely from interactions of their C-terminal peptides, which are reported to cause gate opening by inducing a rocking motion of proteasome alpha subunits rather than by directly contacting the Pro-17 turn. Here we report crystal structures and binding studies of proteasome complexes with PA26 constructs that display modified C-terminal residues, including those corresponding to PAN. These findings suggest that PA26 and PAN/19S C-terminal residues bind superimposably and that both classes of activator induce gate opening by using direct contacts to residues of the proteasome Pro-17 reverse turn. In the case of the PAN and 19S activators, a penultimate tyrosine/phenylalanine residue contacts the proteasome Gly-19 carbonyl oxygen to stabilize the open conformation. Structural models for interactions between the 20S proteasome and its PAN/19S activators.,Stadtmueller BM, Ferrell K, Whitby FG, Heroux A, Robinson H, Myszka DG, Hill CP J Biol Chem. 2010 Jan 1;285(1):13-7. Epub 2009 Nov 4. PMID:19889631 From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See Also Proteasome

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