3JRM

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


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.90 Å
  • R-Value Free: 0.233 
  • R-Value Work: 0.201 
  • R-Value Observed: 0.202 

wwPDB Validation   3D Report Full Report


This is version 1.2 of the entry. See complete history


Literature

Structural models for interactions between the 20S proteasome and its PAN/19S activators.

Stadtmueller, B.M.Ferrell, K.Whitby, F.G.Heroux, A.Robinson, H.Myszka, D.G.Hill, C.P.

(2010) J Biol Chem 285: 13-17

  • DOI: 10.1074/jbc.C109.070425
  • Primary Citation of Related Structures:  
    3JRM, 3JSE, 3JTL

  • PubMed Abstract: 
  • 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 subunit ...

    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.


    Organizational Affiliation

    Department of Biochemistry, University of Utah School of Medicine, Salt Lake City, Utah 84112, USA.



Macromolecules
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Entity ID: 1
MoleculeChainsSequence LengthOrganismDetailsImage
Proteasome subunit alpha ABCDEFG227Thermoplasma acidophilumMutation(s): 0 
Gene Names: psmATa1288
EC: 3.4.25.1
Find proteins for P25156 (Thermoplasma acidophilum (strain ATCC 25905 / DSM 1728 / JCM 9062 / NBRC 15155 / AMRC-C165))
Explore P25156 
Go to UniProtKB:  P25156
Protein Feature View
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  • Reference Sequence
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Entity ID: 2
MoleculeChainsSequence LengthOrganismDetailsImage
Proteasome subunit beta HIJKLMN203Thermoplasma acidophilumMutation(s): 0 
Gene Names: psmBTa0612
EC: 3.4.25.1
Find proteins for P28061 (Thermoplasma acidophilum (strain ATCC 25905 / DSM 1728 / JCM 9062 / NBRC 15155 / AMRC-C165))
Explore P28061 
Go to UniProtKB:  P28061
Protein Feature View
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  • Reference Sequence
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Entity ID: 3
MoleculeChainsSequence LengthOrganismDetailsImage
Proteasome activator protein PA26 OPQRSTU228Trypanosoma bruceiMutation(s): 4 
Find proteins for Q9U8G2 (Trypanosoma brucei)
Explore Q9U8G2 
Go to UniProtKB:  Q9U8G2
Protein Feature View
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  • Reference Sequence
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.90 Å
  • R-Value Free: 0.233 
  • R-Value Work: 0.201 
  • R-Value Observed: 0.202 
  • Space Group: C 1 2 1
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 255.075α = 90
b = 126.363β = 92.54
c = 180.781γ = 90
Software Package:
Software NamePurpose
DENZOdata reduction
SCALEPACKdata scaling
REFMACrefinement
PDB_EXTRACTdata extraction
HKL-2000data collection
REFMACphasing

Structure Validation

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Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2009-11-03
    Type: Initial release
  • Version 1.1: 2011-07-13
    Changes: Version format compliance
  • Version 1.2: 2017-11-01
    Changes: Refinement description