4D79

Crystal structure of E. coli tRNA N6-threonylcarbamoyladenosine dehydratase, TcdA, in complex with ATP at 1.768 Angstroem resolution


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.768 Å
  • R-Value Free: 0.183 
  • R-Value Work: 0.142 

wwPDB Validation 3D Report Full Report


This is version 1.1 of the entry. See complete history

Literature

The Crystal Structure and Small-Angle X-Ray Analysis of Csdl/Tcda Reveal a New tRNA Binding Motif in the Moeb/E1 Superfamily.

Lopez-Estepa, M.Arda, A.Savko, M.Round, A.Shepard, W.E.Bruix, M.Coll, M.Fernandez, F.J.Jimenez-Barbero, J.Vega, M.C.

(2015) Plos One 10: 18606

  • DOI: 10.1371/journal.pone.0118606
  • Primary Citation of Related Structures:  

  • PubMed Abstract: 
  • Cyclic N6-threonylcarbamoyladenosine ('cyclic t6A', ct(6)A) is a non-thiolated hypermodification found in transfer RNAs (tRNAs) in bacteria, protists, fungi and plants. In bacteria and yeast cells ct(6)A has been shown to enhance translation fidelity ...

    Cyclic N6-threonylcarbamoyladenosine ('cyclic t6A', ct(6)A) is a non-thiolated hypermodification found in transfer RNAs (tRNAs) in bacteria, protists, fungi and plants. In bacteria and yeast cells ct(6)A has been shown to enhance translation fidelity and efficiency of ANN codons by improving the faithful discrimination of aminoacylated tRNAs by the ribosome. To further the understanding of ct(6)A biology we have determined the high-resolution crystal structures of CsdL/TcdA in complex with AMP and ATP, an E1-like activating enzyme from Escherichia coli, which catalyzes the ATP-dependent dehydration of t6A to form ct(6)A. CsdL/TcdA is a dimer whose structural integrity and dimer interface depend critically on strongly bound K+ and Na+ cations. By using biochemical assays and small-angle X-ray scattering we show that CsdL/TcdA can associate with tRNA with a 1:1 stoichiometry and with the proper position and orientation for the cyclization of t6A. Furthermore, we show by nuclear magnetic resonance that CsdL/TcdA engages in transient interactions with CsdA and CsdE, which, in the latter case, involve catalytically important residues. These short-lived interactions may underpin the precise channeling of sulfur atoms from cysteine to CsdL/TcdA as previously characterized. In summary, the combination of structural, biophysical and biochemical methods applied to CsdL/TcdA has afforded a more thorough understanding of how the structure of this E1-like enzyme has been fine tuned to accomplish ct(6)A synthesis on tRNAs while providing support for the notion that CsdA and CsdE are able to functionally interact with CsdL/TcdA.


    Organizational Affiliation

    Chemical and Physical Biology, Center for Biological Research (CIB-CSIC), Madrid, Spain.




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
TRNA THREONYLCARBAMOYLADENOSINE DEHYDRATASE
A, B, C, D
276Escherichia coli (strain K12)Mutation(s): 0 
Gene Names: tcdA (csdL, ygdL)
EC: 6.1.-.-
Find proteins for Q46927 (Escherichia coli (strain K12))
Go to UniProtKB:  Q46927
Small Molecules
Ligands 4 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
K
Query on K

Download SDF File 
Download CCD File 
A, B, C, D
POTASSIUM ION
K
NPYPAHLBTDXSSS-UHFFFAOYSA-N
 Ligand Interaction
ATP
Query on ATP

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Download CCD File 
A, B, C, D
ADENOSINE-5'-TRIPHOSPHATE
C10 H16 N5 O13 P3
ZKHQWZAMYRWXGA-KQYNXXCUSA-N
 Ligand Interaction
NA
Query on NA

Download SDF File 
Download CCD File 
B, D
SODIUM ION
Na
FKNQFGJONOIPTF-UHFFFAOYSA-N
 Ligand Interaction
GOL
Query on GOL

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Download CCD File 
A, B, C, D
GLYCEROL
GLYCERIN; PROPANE-1,2,3-TRIOL
C3 H8 O3
PEDCQBHIVMGVHV-UHFFFAOYSA-N
 Ligand Interaction
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.768 Å
  • R-Value Free: 0.183 
  • R-Value Work: 0.142 
  • Space Group: P 1 21 1
Unit Cell:
Length (Å)Angle (°)
a = 65.690α = 90.00
b = 97.160β = 111.61
c = 83.190γ = 90.00
Software Package:
Software NamePurpose
PHASERphasing
XDSdata reduction
Aimlessdata scaling
PHENIXrefinement

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2015-05-06
    Type: Initial release
  • Version 1.1: 2017-01-25
    Type: Data collection