7NZI

TrmB complex with SAH


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 3.10 Å
  • R-Value Free: 0.291 
  • R-Value Work: 0.231 
  • R-Value Observed: 0.234 

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Ligand Structure Quality Assessment 


This is version 1.2 of the entry. See complete history


Literature

Structural model of the M7G46 Methyltransferase TrmB in complex with tRNA.

Blersch, K.F.Burchert, J.P.August, S.C.Welp, L.Neumann, P.Koster, S.Urlaub, H.Ficner, R.

(2021) RNA Biol 18: 2466-2479

  • DOI: https://doi.org/10.1080/15476286.2021.1925477
  • Primary Citation of Related Structures:  
    7NYB, 7NZI, 7NZJ

  • PubMed Abstract: 

    TrmB belongs to the class I S-adenosylmethionine (SAM)-dependent methyltransferases (MTases) and introduces a methyl group to guanine at position 7 (m 7 G) in tRNA. In tRNAs m 7 G is most frequently found at position 46 in the variable loop and forms a tertiary base pair with C13 and U22, introducing a positive charge at G46. The TrmB/Trm8 enzyme family is structurally diverse, as TrmB proteins exist in a monomeric, homodimeric, and heterodimeric form. So far, the exact enzymatic mechanism, as well as the tRNA-TrmB crystal structure is not known. Here we present the first crystal structures of B. subtilis TrmB in complex with SAM and SAH. The crystal structures of TrmB apo and in complex with SAM and SAH have been determined by X-ray crystallography to 1.9 Å (apo), 2.5 Å (SAM), and 3.1 Å (SAH). The obtained crystal structures revealed Tyr193 to be important during SAM binding and MTase activity. Applying fluorescence polarization, the dissociation constant K d of TrmB and tRNA Phe was determined to be 0.12 µM ± 0.002 µM. Luminescence-based methyltransferase activity assays revealed cooperative effects during TrmB catalysis with half-of-the-site reactivity at physiological SAM concentrations. Structural data retrieved from small-angle x-ray scattering (SAXS), mass-spectrometry of cross-linked complexes, and molecular docking experiments led to the determination of the TrmB-tRNA Phe complex structure.


  • Organizational Affiliation

    Department of Molecular Structural Biology, Institute of Microbiology and Genetics, GZMB, Georg August University Göttingen, Göttingen, Germany.


Macromolecules
Find similar proteins by:  (by identity cutoff)  |  3D Structure
Entity ID: 1
MoleculeChains Sequence LengthOrganismDetailsImage
tRNA (guanine-N(7)-)-methyltransferase
A, B
213Bacillus subtilis subsp. subtilis str. 168Mutation(s): 0 
Gene Names: trmBytmQBSU29900
EC: 2.1.1.33
UniProt
Find proteins for O34522 (Bacillus subtilis (strain 168))
Explore O34522 
Go to UniProtKB:  O34522
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupO34522
Sequence Annotations
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  • Reference Sequence
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 3.10 Å
  • R-Value Free: 0.291 
  • R-Value Work: 0.231 
  • R-Value Observed: 0.234 
  • Space Group: H 3
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 177.48α = 90
b = 177.48β = 90
c = 42.44γ = 120
Software Package:
Software NamePurpose
REFMACrefinement
XDSdata reduction
XSCALEdata scaling
PDB_EXTRACTdata extraction
PHASERphasing

Structure Validation

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Ligand Structure Quality Assessment 


Entry History & Funding Information

Deposition Data


Funding OrganizationLocationGrant Number
German Research Foundation (DFG)Germany--

Revision History  (Full details and data files)

  • Version 1.0: 2021-09-15
    Type: Initial release
  • Version 1.1: 2021-12-01
    Changes: Database references
  • Version 1.2: 2024-01-31
    Changes: Data collection, Refinement description