Crystal structure of the hypothetical protein STK_08120 from Sulfolobus tokodaii

Experimental Data Snapshot

  • Resolution: 1.79 Å
  • R-Value Free: 0.262 
  • R-Value Work: 0.220 
  • R-Value Observed: 0.222 

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A thermoacidophile-specific protein family, DUF3211, functions as a fatty acid carrier with novel binding mode

Miyakawa, T.Sawano, Y.Miyazono, K.Miyauchi, Y.Hatano, K.Tanokura, M.

(2013) J Bacteriol 195: 4005-4012

  • DOI: https://doi.org/10.1128/JB.00432-13
  • Primary Citation of Related Structures:  
    2EJX, 3W9K

  • PubMed Abstract: 

    STK_08120 is a member of the thermoacidophile-specific DUF3211 protein family from Sulfolobus tokodaii strain 7. Its molecular function remains obscure, and sequence similarities for obtaining functional remarks are not available. In this study, the crystal structure of STK_08120 was determined at 1.79-Å resolution to predict its probable function using structure similarity searches. The structure adopts an α/β structure of a helix-grip fold, which is found in the START domain proteins with cavities for hydrophobic substrates or ligands. The detailed structural features implied that fatty acids are the primary ligand candidates for STK_08120, and binding assays revealed that the protein bound long-chain saturated fatty acids (>C14) and their trans-unsaturated types with an affinity equal to that for major fatty acid binding proteins in mammals and plants. Moreover, the structure of an STK_08120-myristic acid complex revealed a unique binding mode among fatty acid binding proteins. These results suggest that the thermoacidophile-specific protein family DUF3211 functions as a fatty acid carrier with a novel binding mode.

  • Organizational Affiliation

    Department of Applied Biological Chemistry, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Tokyo, Japan.

Find similar proteins by:  (by identity cutoff)  |  3D Structure
Entity ID: 1
MoleculeChains Sequence LengthOrganismDetailsImage
STK_08120139Sulfurisphaera tokodaii str. 7Mutation(s): 0 
Gene Names: STK_08120
Find proteins for Q973T5 (Sulfurisphaera tokodaii (strain DSM 16993 / JCM 10545 / NBRC 100140 / 7))
Explore Q973T5 
Go to UniProtKB:  Q973T5
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupQ973T5
Sequence Annotations
  • Reference Sequence
Experimental Data & Validation

Experimental Data

  • Resolution: 1.79 Å
  • R-Value Free: 0.262 
  • R-Value Work: 0.220 
  • R-Value Observed: 0.222 
  • Space Group: P 21 21 2
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 54.887α = 90
b = 70.446β = 90
c = 35.23γ = 90
Software Package:
Software NamePurpose
HKL-2000data collection
HKL-2000data reduction
HKL-2000data scaling

Structure Validation

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Entry History 

Deposition Data

Revision History  (Full details and data files)

  • Version 1.0: 2008-03-25
    Type: Initial release
  • Version 1.1: 2011-07-13
    Changes: Version format compliance
  • Version 1.2: 2013-07-17
    Changes: Database references
  • Version 1.3: 2013-11-06
    Changes: Database references
  • Version 1.4: 2024-03-13
    Changes: Data collection, Database references