6D14

Zebrafish TRAP1 bound to AMPPNP and calcium in the asymmetric closed state

  • Classification: CHAPERONE
  • Organism(s): Danio rerio
  • Expression System: Escherichia coli
  • Mutation(s): No 

  • Deposited: 2018-04-11 Released: 2018-04-25 
  • Deposition Author(s): Elnatan, D., Agard, D.A.
  • Funding Organization(s): National Institutes of Health/National Institute of General Medical Sciences (NIH/NIGMS), Howard Hughes Medical Institute (HHMI)

Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.50 Å
  • R-Value Free: 0.255 
  • R-Value Work: 0.230 
  • R-Value Observed: 0.231 

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This is version 1.3 of the entry. See complete history


Literature

Calcium binding to a remote site can replace magnesium as cofactor for mitochondrial Hsp90 (TRAP1) ATPase activity.

Elnatan, D.Agard, D.A.

(2018) J Biol Chem 293: 13717-13724

  • DOI: https://doi.org/10.1074/jbc.RA118.003562
  • Primary Citation of Related Structures:  
    6D14

  • PubMed Abstract: 

    The Hsp90 molecular chaperones are ATP-dependent enzymes that maintain protein homeostasis and regulate many essential cellular processes. Higher eukaryotes have organelle-specific Hsp90 paralogs that are adapted to each subcellular environment. The mitochondrial Hsp90, TNF receptor-associated protein 1 (TRAP1), supports the folding and activity of electron transport components and is increasingly appreciated as a critical player in mitochondrial signaling. Calcium plays a well-known and important regulatory role in mitochondria where it can accumulate to much higher concentrations than in the cytoplasm. Surprisingly, we found here that calcium can replace magnesium, the essential enzymatic cofactor, to support TRAP1 ATPase activity. Anomalous X-ray diffraction experiments revealed a calcium-binding site within the TRAP1 nucleotide-binding pocket located near the ATP α-phosphate and completely distinct from the magnesium-binding site adjacent to the β- and γ-phosphates. In the presence of magnesium, ATP hydrolysis by TRAP1, as with other Hsp90s, was noncooperative, whereas calcium binding resulted in cooperative hydrolysis by the two protomers within the Hsp90 dimer. The structural data suggested a mechanism for this cooperative behavior. Because of the cooperativity, at high ATP concentrations, ATPase activity was higher with calcium, whereas the converse was observed at low ATP concentrations. Integrating these observations, we propose a model in which the divalent cation choice can control switching between noncooperative and cooperative TRAP1 ATPase mechanisms in response to varying ATP concentrations. This switching may facilitate coordination between cellular energetics, mitochondrial signaling, and protein homeostasis via alterations in the TRAP1 ATP-driven cycle and its consequent effects on different mitochondrial clients.


  • Organizational Affiliation

    From the Howard Hughes Medical Institute and the Department of Biochemistry and Biophysics, University of California at San Francisco, San Francisco, California 94158-2517.


Macromolecules
Find similar proteins by:  (by identity cutoff)  |  3D Structure
Entity ID: 1
MoleculeChains Sequence LengthOrganismDetailsImage
TNF receptor-associated protein 1
A, B
635Danio rerioMutation(s): 0 
Gene Names: trap1
UniProt
Find proteins for A8WFV1 (Danio rerio)
Explore A8WFV1 
Go to UniProtKB:  A8WFV1
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupA8WFV1
Sequence Annotations
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  • Reference Sequence
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.50 Å
  • R-Value Free: 0.255 
  • R-Value Work: 0.230 
  • R-Value Observed: 0.231 
  • Space Group: C 1 2 1
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 176.252α = 90
b = 95.751β = 134.66
c = 124.546γ = 90
Software Package:
Software NamePurpose
REFMACrefinement
XSCALEdata scaling
PDB_EXTRACTdata extraction
XDSdata reduction
PHASERphasing

Structure Validation

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Ligand Structure Quality Assessment 


Entry History & Funding Information

Deposition Data


Funding OrganizationLocationGrant Number
National Institutes of Health/National Institute of General Medical Sciences (NIH/NIGMS)United StatesU01 GM098254
Howard Hughes Medical Institute (HHMI)United States--

Revision History  (Full details and data files)

  • Version 1.0: 2018-04-25
    Type: Initial release
  • Version 1.1: 2019-11-06
    Changes: Data collection, Database references
  • Version 1.2: 2019-11-20
    Changes: Author supporting evidence
  • Version 1.3: 2023-10-04
    Changes: Data collection, Database references, Derived calculations, Refinement description