6Q56

Crystal structure of the B. subtilis M1A22 tRNA methyltransferase TrmK


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.00 Å
  • R-Value Free: 0.237 
  • R-Value Work: 0.212 
  • R-Value Observed: 0.214 

Starting Model: experimental
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wwPDB Validation   3D Report Full Report


This is version 1.3 of the entry. See complete history


Literature

Structural characterization of B. subtilis m1A22 tRNA methyltransferase TrmK: insights into tRNA recognition.

Degut, C.Roovers, M.Barraud, P.Brachet, F.Feller, A.Larue, V.Al Refaii, A.Caillet, J.Droogmans, L.Tisne, C.

(2019) Nucleic Acids Res 47: 4736-4750

  • DOI: https://doi.org/10.1093/nar/gkz230
  • Primary Citation of Related Structures:  
    6Q56

  • PubMed Abstract: 

    1-Methyladenosine (m1A) is a modified nucleoside found at positions 9, 14, 22 and 58 of tRNAs, which arises from the transfer of a methyl group onto the N1-atom of adenosine. The yqfN gene of Bacillus subtilis encodes the methyltransferase TrmK (BsTrmK) responsible for the formation of m1A22 in tRNA. Here, we show that BsTrmK displays a broad substrate specificity, and methylates seven out of eight tRNA isoacceptor families of B. subtilis bearing an A22. In addition to a non-Watson-Crick base-pair between the target A22 and a purine at position 13, the formation of m1A22 by BsTrmK requires a full-length tRNA with intact tRNA elbow and anticodon stem. We solved the crystal structure of BsTrmK showing an N-terminal catalytic domain harbouring the typical Rossmann-like fold of Class-I methyltransferases and a C-terminal coiled-coil domain. We used NMR chemical shift mapping to drive the docking of BstRNASer to BsTrmK in complex with its methyl-donor cofactor S-adenosyl-L-methionine (SAM). In this model, validated by methyltransferase activity assays on BsTrmK mutants, both domains of BsTrmK participate in tRNA binding. BsTrmK recognises tRNA with very few structural changes in both partner, the non-Watson-Crick R13-A22 base-pair positioning the A22 N1-atom close to the SAM methyl group.


  • Organizational Affiliation

    Laboratoire de Cristallographie et RMN biologiques, CNRS, Université Paris Descartes, Sorbonne Paris Cité, 4 avenue de l'Observatoire, 75006 Paris, France.


Macromolecules
Find similar proteins by:  (by identity cutoff)  |  3D Structure
Entity ID: 1
MoleculeChains Sequence LengthOrganismDetailsImage
tRNA (adenine(22)-N(1))-methyltransferase
A, B, C, D
238Bacillus subtilis subsp. subtilis str. 168Mutation(s): 2 
Gene Names: trmKyqfNBSU25180
EC: 2.1.1.217
UniProt
Find proteins for P54471 (Bacillus subtilis (strain 168))
Explore P54471 
Go to UniProtKB:  P54471
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupP54471
Sequence Annotations
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  • Reference Sequence
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.00 Å
  • R-Value Free: 0.237 
  • R-Value Work: 0.212 
  • R-Value Observed: 0.214 
  • Space Group: P 1 21 1
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 81.56α = 90
b = 51.98β = 110.6
c = 108.13γ = 90
Software Package:
Software NamePurpose
PHENIXrefinement
XDSdata reduction
XDSdata scaling
PHASERphasing

Structure Validation

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Entry History 

Deposition Data

Revision History  (Full details and data files)

  • Version 1.0: 2019-03-27
    Type: Initial release
  • Version 1.1: 2019-04-10
    Changes: Data collection, Database references
  • Version 1.2: 2019-05-22
    Changes: Data collection, Database references
  • Version 1.3: 2024-01-24
    Changes: Data collection, Database references, Derived calculations, Refinement description