2PWY

Crystal Structure of a m1A58 tRNA methyltransferase


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.70 Å
  • R-Value Free: 0.209 
  • R-Value Work: 0.180 
  • R-Value Observed: 0.181 

wwPDB Validation 3D Report Full Report


This is version 1.1 of the entry. See complete history


Literature

Crystal Structure of Thermus thermophilus tRNA m(1)A(58) Methyltransferase and Biophysical Characterization of Its Interaction with tRNA.

Barraud, P.Golinelli-Pimpaneau, B.Atmanene, C.Sanglier, S.Van Dorsselaer, A.Droogmans, L.Dardel, F.Tisne, C.

(2008) J Mol Biol 377: 535-550

  • DOI: 10.1016/j.jmb.2008.01.041
  • Structures With Same Primary Citation

  • PubMed Abstract: 
  • Methyltransferases from the m(1)A(58) tRNA methyltransferase (TrmI) family catalyze the S-adenosyl-l-methionine-dependent N(1)-methylation of tRNA adenosine 58. The crystal structure of Thermus thermophilus TrmI, in complex with S-adenosyl-l-homocyst ...

    Methyltransferases from the m(1)A(58) tRNA methyltransferase (TrmI) family catalyze the S-adenosyl-l-methionine-dependent N(1)-methylation of tRNA adenosine 58. The crystal structure of Thermus thermophilus TrmI, in complex with S-adenosyl-l-homocysteine, was determined at 1.7 A resolution. This structure is closely related to that of Mycobacterium tuberculosis TrmI, and their comparison enabled us to enlighten two grooves in the TrmI structure that are large enough and electrostatically compatible to accommodate one tRNA per face of TrmI tetramer. We have then conducted a biophysical study based on electrospray ionization mass spectrometry, site-directed mutagenesis, and molecular docking. First, we confirmed the tetrameric oligomerization state of TrmI, and we showed that this protein remains tetrameric upon tRNA binding, with formation of complexes involving one to two molecules of tRNA per TrmI tetramer. Second, three key residues for the methylation reaction were identified: the universally conserved D170 and two conserved aromatic residues Y78 and Y194. We then used molecular docking to position a N(9)-methyladenine in the active site of TrmI. The N(9)-methyladenine snugly fits into the catalytic cleft, where the side chain of D170 acts as a bidentate ligand binding the amino moiety of S-adenosyl-l-methionine and the exocyclic amino group of the adenosine. Y194 interacts with the N(9)-methyladenine ring, whereas Y78 can stabilize the sugar ring. From our results, we propose that the conserved residues that form the catalytic cavity (D170, Y78, and Y194) are essential for fashioning an optimized shape of the catalytic pocket.


    Organizational Affiliation

    Laboratoire de Cristallographie et RMN biologiques, Université Paris-Descartes, CNRS UMR 8015, 4 avenue de l'Observatoire, 75006 Paris, France.



Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
tRNA (adenine-N(1)-)-methyltransferase
A, B
258Thermus thermophilus HB27Mutation(s): 0 
Gene Names: trmITT_C0244
EC: 2.1.1.36 (PDB Primary Data), 2.1.1.220 (UniProt)
Find proteins for Q8GBB2 (Thermus thermophilus (strain HB27 / ATCC BAA-163 / DSM 7039))
Go to UniProtKB:  Q8GBB2
Protein Feature View
  • Reference Sequence
Small Molecules
Ligands 2 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
SAH
Query on SAH

Download CCD File 
A
S-ADENOSYL-L-HOMOCYSTEINE
C14 H20 N6 O5 S
ZJUKTBDSGOFHSH-WFMPWKQPSA-N
 Ligand Interaction
SO4
Query on SO4

Download CCD File 
A, B
SULFATE ION
O4 S
QAOWNCQODCNURD-UHFFFAOYSA-L
 Ligand Interaction
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.70 Å
  • R-Value Free: 0.209 
  • R-Value Work: 0.180 
  • R-Value Observed: 0.181 
  • Space Group: C 2 2 21
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 90.44α = 90
b = 96.795β = 90
c = 140.584γ = 90
Software Package:
Software NamePurpose
SCALAdata scaling
PHASERphasing
REFMACrefinement
PDB_EXTRACTdata extraction
MxCuBEdata collection
MOSFLMdata reduction

Structure Validation

View Full Validation Report



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2008-02-26
    Type: Initial release
  • Version 1.1: 2011-07-13
    Changes: Advisory, Source and taxonomy, Version format compliance