8E18

Crystal structure of apo TnmK1


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.14 Å
  • R-Value Free: 0.153 
  • R-Value Work: 0.133 
  • R-Value Observed: 0.134 

Starting Model: experimental
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wwPDB Validation   3D Report Full Report


This is version 1.2 of the entry. See complete history


Literature

Intramolecular C-C Bond Formation Links Anthraquinone and Enediyne Scaffolds in Tiancimycin Biosynthesis.

Gui, C.Kalkreuter, E.Liu, Y.C.Adhikari, A.Teijaro, C.N.Yang, D.Chang, C.Shen, B.

(2022) J Am Chem Soc 144: 20452-20462

  • DOI: https://doi.org/10.1021/jacs.2c08957
  • Primary Citation of Related Structures:  
    8E18, 8E19

  • PubMed Abstract: 

    First discovered in 1989, the anthraquinone-fused enediynes are a class of DNA-cleaving bacterial natural products composed of a DNA-intercalating anthraquinone moiety and a 10-membered enediyne warhead. However, until recently, there has been a lack of genetically amenable hosts and sequenced biosynthetic gene clusters available for solving the biosynthetic questions surrounding these molecules. Herein, we have identified and biochemically and structurally characterized TnmK1, a member of the α/β-hydrolase fold superfamily responsible for the C-C bond formation linking the anthraquinone moiety and enediyne core together in tiancimycin (TNM) biosynthesis. In doing so, two intermediates, TNM H and TNM I, in anthraquinone-fused enediyne biosynthesis, containing an unprecedented cryptic C16 aldehyde group, were identified. This aldehyde plays a key role in the TnmK1-catalyzed C-C bond formation via a Michael addition, representing the first example of this chemistry for the α/β-hydrolase fold superfamily. Additionally, TNM I shows sub-nanomolar cytotoxicity against selected cancer cell lines, indicating a new mechanism of action compared to previously known anthraquinone-fused enediynes. Together, the findings from this study are expected to impact enzymology, natural product biosynthesis, and future efforts at enediyne discovery and drug development.


  • Organizational Affiliation

    Skaggs Graduate School of Chemical and Biological Sciences, Scripps Research, Jupiter, Florida 33458, United States.


Macromolecules
Find similar proteins by:  (by identity cutoff)  |  3D Structure
Entity ID: 1
MoleculeChains Sequence LengthOrganismDetailsImage
Secreted hydrolase484Streptomyces sp. CB03234Mutation(s): 0 
Gene Names: tnmK1AMK26_32035
UniProt
Find proteins for A0A125SA14 (Streptomyces sp. (strain CB03234))
Explore A0A125SA14 
Go to UniProtKB:  A0A125SA14
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupA0A125SA14
Sequence Annotations
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  • Reference Sequence
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.14 Å
  • R-Value Free: 0.153 
  • R-Value Work: 0.133 
  • R-Value Observed: 0.134 
  • Space Group: P 41 21 2
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 86.006α = 90
b = 86.006β = 90
c = 132.392γ = 90
Software Package:
Software NamePurpose
REFMACrefinement
PHENIXrefinement
HKL-2000data reduction
HKL-2000data scaling
MrBUMPphasing

Structure Validation

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Entry History & Funding Information

Deposition Data


Funding OrganizationLocationGrant Number
National Institutes of Health/National Institute of General Medical Sciences (NIH/NIGMS)United StatesGM134954

Revision History  (Full details and data files)

  • Version 1.0: 2022-11-09
    Type: Initial release
  • Version 1.1: 2022-11-16
    Changes: Database references
  • Version 1.2: 2023-10-18
    Changes: Data collection, Refinement description