QTRT2, the non-catalytic subunit of murine tRNA-Guanine Transglycosylase

Experimental Data Snapshot

  • Resolution: 2.18 Å
  • R-Value Free: 0.207 
  • R-Value Work: 0.170 
  • R-Value Observed: 0.171 

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This is version 1.2 of the entry. See complete history


Homodimer Architecture of QTRT2, the Noncatalytic Subunit of the Eukaryotic tRNA-Guanine Transglycosylase.

Behrens, C.Biela, I.Petiot-Becard, S.Botzanowski, T.Cianferani, S.Sager, C.P.Klebe, G.Heine, A.Reuter, K.

(2018) Biochemistry 57: 3953-3965

  • DOI: https://doi.org/10.1021/acs.biochem.8b00294
  • Primary Citation of Related Structures:  

  • PubMed Abstract: 

    The bacterial enzyme tRNA-guanine transglycosylase (TGT) is involved in the biosynthesis of queuosine, a modified nucleoside present in the anticodon wobble position of tRNA His , tRNA Tyr , tRNA Asp , and tRNA Asn . Although it forms a stable homodimer endowed with two active sites, it is, for steric reasons, able to bind and convert only one tRNA molecule at a time. In contrast, its mammalian counterpart constitutes a heterodimer consisting of a catalytic and a noncatalytic subunit, termed QTRT1 and QTRT2, respectively. Both subunits are homologous to the bacterial enzyme, yet only QTRT1 possesses all the residues required for substrate binding and catalysis. In mice, genetic inactivation of the TGT results in the uncontrolled oxidation of tetrahydrobiopterin and, accordingly, phenylketonuria-like symptoms. For this reason and because of the recent finding that mammalian TGT may be utilized for the treatment of multiple sclerosis, this enzyme is of potential medical relevance, rendering detailed knowledge of its biochemistry and structural architecture highly desirable. In this study, we performed the kinetic characterization of the murine enzyme, investigated potential quaternary structures of QTRT1 and QTRT2 via noncovalent mass spectrometry, and, finally, determined the crystal structure of the murine noncatalytic TGT subunit, QTRT2. In the crystal, QTRT2 is clearly present as a homodimer that is strikingly similar to that formed by bacterial TGT. In particular, a cluster of four aromatic residues within the interface of the bacterial TGT, which constitutes a "hot spot" for dimer stability, is present in a similar constellation in QTRT2.

  • Organizational Affiliation

    Institut für Pharmazeutische Chemie , Philipps-Universität Marburg , Marbacher Weg 6 , D-35032 Marburg , Germany.

Find similar proteins by:  (by identity cutoff)  |  3D Structure
Entity ID: 1
MoleculeChains Sequence LengthOrganismDetailsImage
Queuine tRNA-ribosyltransferase accessory subunit 2
A, B
423Mus musculusMutation(s): 0 
Gene Names: Qtrt2Qtrtd1
Find proteins for B8ZXI1 (Mus musculus)
Explore B8ZXI1 
Go to UniProtKB:  B8ZXI1
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupB8ZXI1
Sequence Annotations
  • Reference Sequence
Experimental Data & Validation

Experimental Data

  • Resolution: 2.18 Å
  • R-Value Free: 0.207 
  • R-Value Work: 0.170 
  • R-Value Observed: 0.171 
  • Space Group: P 21 21 2
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 118.475α = 90
b = 124.573β = 90
c = 61.849γ = 90
Software Package:
Software NamePurpose
XDSdata reduction
XDSdata scaling
Cootmodel building

Structure Validation

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Entry History 

Deposition Data

Revision History  (Full details and data files)

  • Version 1.0: 2018-06-13
    Type: Initial release
  • Version 1.1: 2018-07-11
    Changes: Data collection, Database references
  • Version 1.2: 2024-05-08
    Changes: Data collection, Database references