Structure of human IST1(NTD) - (residues 1-189)(P21)

Experimental Data Snapshot

  • Resolution: 1.80 Å
  • R-Value Free: 0.247 
  • R-Value Work: 0.195 
  • R-Value Observed: 0.197 

Starting Model: experimental
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Structural basis for ESCRT-III protein autoinhibition.

Bajorek, M.Schubert, H.L.McCullough, J.Langelier, C.Eckert, D.M.Stubblefield, W.M.Uter, N.T.Myszka, D.G.Hill, C.P.Sundquist, W.I.

(2009) Nat Struct Mol Biol 16: 754-762

  • DOI: https://doi.org/10.1038/nsmb.1621
  • Primary Citation of Related Structures:  
    3FRR, 3FRS, 3FRT, 3FRV

  • PubMed Abstract: 

    Endosomal sorting complexes required for transport-III (ESCRT-III) subunits cycle between two states: soluble monomers and higher-order assemblies that bind and remodel membranes during endosomal vesicle formation, midbody abscission and enveloped virus budding. Here we show that the N-terminal core domains of increased sodium tolerance-1 (IST1) and charged multivesicular body protein-3 (CHMP3) form equivalent four-helix bundles, revealing that IST1 is a previously unrecognized ESCRT-III family member. IST1 and its ESCRT-III binding partner, CHMP1B, both form higher-order helical structures in vitro, and IST1-CHMP1 interactions are required for abscission. The IST1 and CHMP3 structures also reveal that equivalent downstream alpha5 helices can fold back against the core domains. Mutations within the CHMP3 core-alpha5 interface stimulate the protein's in vitro assembly and HIV-inhibition activities, indicating that dissociation of the autoinhibitory alpha5 helix from the core activates ESCRT-III proteins for assembly at membranes.

  • Organizational Affiliation

    Department of Biochemistry, University of Utah, Salt Lake City, Utah, USA.

Find similar proteins by:  (by identity cutoff)  |  3D Structure
Entity ID: 1
MoleculeChains Sequence LengthOrganismDetailsImage
Uncharacterized protein KIAA0174191Homo sapiensMutation(s): 0 
Gene Names: IST1KIAA0174
UniProt & NIH Common Fund Data Resources
Find proteins for P53990 (Homo sapiens)
Explore P53990 
Go to UniProtKB:  P53990
PHAROS:  P53990
GTEx:  ENSG00000182149 
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupP53990
Sequence Annotations
  • Reference Sequence
Experimental Data & Validation

Experimental Data

  • Resolution: 1.80 Å
  • R-Value Free: 0.247 
  • R-Value Work: 0.195 
  • R-Value Observed: 0.197 
  • Space Group: P 1 21 1
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 29.251α = 90
b = 92.364β = 97.02
c = 33.251γ = 90
Software Package:
Software NamePurpose
DENZOdata reduction
SCALEPACKdata scaling
PDB_EXTRACTdata extraction
CrystalCleardata collection

Structure Validation

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Entry History 

Deposition Data

Revision History  (Full details and data files)

  • Version 1.0: 2009-06-30
    Type: Initial release
  • Version 1.1: 2011-07-13
    Changes: Version format compliance
  • Version 1.2: 2017-11-01
    Changes: Refinement description
  • Version 1.3: 2023-09-06
    Changes: Data collection, Database references, Refinement description