2ZPA

Crystal Structure of tRNA(Met) Cytidine Acetyltransferase


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.35 Å
  • R-Value Free: 0.274 
  • R-Value Work: 0.235 

wwPDB Validation 3D Report Full Report


This is version 1.1 of the entry. See complete history

Literature

RNA helicase module in an acetyltransferase that modifies a specific tRNA anticodon

Chimnaronk, S.Suzuki, T.Manita, T.Ikeuchi, Y.Yao, M.Suzuki, T.Tanaka, I.

(2009) Embo J. 28: 1362-1373

  • DOI: 10.1038/emboj.2009.69

  • PubMed Abstract: 
  • Post-transcriptional RNA modifications in the anticodon of transfer RNAs frequently contribute to the high fidelity of protein synthesis. In eubacteria, two genome-encoded transfer RNA (tRNA) species bear the same CAU sequence as the anticodons, whic ...

    Post-transcriptional RNA modifications in the anticodon of transfer RNAs frequently contribute to the high fidelity of protein synthesis. In eubacteria, two genome-encoded transfer RNA (tRNA) species bear the same CAU sequence as the anticodons, which are differentiated by modified cytidines at the wobble positions. The elongator tRNA(Met) accepts an acetyl moiety at the wobble base to form N(4)-acetylcytidine (ac(4)C): an inherent modification ensures precise decoding of the AUG codon by strengthening C-G base-pair interaction and concurrently preventing misreading of the near cognate AUA codon. We have determined the crystal structure of tRNA(Met) cytidine acetyltransferase (TmcA) from Escherichia coli complexed with two natural ligands, acetyl-CoA and ADP, at 2.35 A resolution. The structure unexpectedly reveals an idiosyncratic RNA helicase module fused with a GCN5-related N-acetyltransferase (GNAT) fold, which intimately cross-interact. Taken together with the biochemical evidence, we further unravelled the function of acetyl-CoA as an enzyme-activating switch, and propose that an RNA helicase motor driven by ATP hydrolysis is used to deliver the wobble base to the active centre of the GNAT domain.


    Organizational Affiliation

    Faculty of Advanced Life Sciences, Hokkaido University, Sapporo, Japan.




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
Uncharacterized protein ypfI
A, B
671Escherichia coli (strain K12)Gene Names: tmcA (ypfI)
EC: 2.3.1.193
Find proteins for P76562 (Escherichia coli (strain K12))
Go to UniProtKB:  P76562
Small Molecules
Ligands 3 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
ACO
Query on ACO

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Download CCD File 
A, B
ACETYL COENZYME *A
C23 H38 N7 O17 P3 S
ZSLZBFCDCINBPY-ZSJPKINUSA-N
 Ligand Interaction
SO4
Query on SO4

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Download CCD File 
B
SULFATE ION
O4 S
QAOWNCQODCNURD-UHFFFAOYSA-L
 Ligand Interaction
ADP
Query on ADP

Download SDF File 
Download CCD File 
A
ADENOSINE-5'-DIPHOSPHATE
C10 H15 N5 O10 P2
XTWYTFMLZFPYCI-KQYNXXCUSA-N
 Ligand Interaction
Modified Residues  1 Unique
IDChainsTypeFormula2D DiagramParent
MSE
Query on MSE
A, B
L-PEPTIDE LINKINGC5 H11 N O2 SeMET
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.35 Å
  • R-Value Free: 0.274 
  • R-Value Work: 0.235 
  • Space Group: P 21 21 21
Unit Cell:
Length (Å)Angle (°)
a = 61.298α = 90.00
b = 100.990β = 90.00
c = 263.116γ = 90.00
Software Package:
Software NamePurpose
CNSrefinement
HKL-2000data reduction
SOLVEphasing
HKL-2000data scaling

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2009-04-07
    Type: Initial release
  • Version 1.1: 2011-07-13
    Type: Version format compliance