PDBsum entry 1p0d

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protein metals links
Transferase PDB id
Protein chain
363 a.a. *
Waters ×358
* Residue conservation analysis
PDB id:
Name: Transferase
Title: Crystal structure of zymomonas mobilis tRNA-guanine transgly (tgt) crystallised at ph 5.5
Structure: Queuine tRNA-ribosyltransferase. Chain: a. Synonym: tRNA-guanine transglycosylase, guanine insertion e engineered: yes
Source: Zymomonas mobilis. Organism_taxid: 542. Gene: tgt. Expressed in: escherichia coli bl21(de3). Expression_system_taxid: 469008.
Biol. unit: Dimer (from PQS)
1.90Å     R-factor:   0.172     R-free:   0.209
Authors: R.Brenk,M.T.Stubbs,A.Heine,K.Reuter,G.Klebe
Key ref: R.Brenk et al. (2003). Flexible adaptations in the structure of the tRNA-modifying enzyme tRNA-guanine transglycosylase and their implications for substrate selectivity, reaction mechanism and structure-based drug design. Chembiochem, 4, 1066-1077. PubMed id: 14523925 DOI: 10.1002/cbic.200300644
10-Apr-03     Release date:   30-Sep-03    
Go to PROCHECK summary

Protein chain
Pfam   ArchSchema ?
P28720  (TGT_ZYMMO) -  Queuine tRNA-ribosyltransferase
386 a.a.
363 a.a.*
Key:    PfamA domain  Secondary structure  CATH domain
* PDB and UniProt seqs differ at 1 residue position (black cross)

 Enzyme reactions 
   Enzyme class: E.C.  - tRNA-guanine(34) transglycosylase.
[IntEnz]   [ExPASy]   [KEGG]   [BRENDA]
1. Guanine34 in tRNA + queuine = queuosine34 in tRNA + guanine
2. Guanine34 in tRNA + 7-aminomethyl-7-carbaguanine = 7-aminomethyl-7- carbaguanine34 in tRNA + guanine
Guanine(34) in tRNA
+ queuine
= queuosine(34) in tRNA
+ guanine
Guanine(34) in tRNA
+ 7-aminomethyl-7-carbaguanine
= 7-aminomethyl-7- carbaguanine(34) in tRNA
+ guanine
Molecule diagrams generated from .mol files obtained from the KEGG ftp site
 Gene Ontology (GO) functional annotation 
  GO annot!
  Biological process     tRNA processing   3 terms 
  Biochemical function     transferase activity     4 terms  


DOI no: 10.1002/cbic.200300644 Chembiochem 4:1066-1077 (2003)
PubMed id: 14523925  
Flexible adaptations in the structure of the tRNA-modifying enzyme tRNA-guanine transglycosylase and their implications for substrate selectivity, reaction mechanism and structure-based drug design.
R.Brenk, M.T.Stubbs, A.Heine, K.Reuter, G.Klebe.
The enzyme tRNA-guanine transglycosylase (TGT, EC catalyses a base-exchange reaction that leads to anticodon modifications of certain tRNAs. The TGT enzymes of the eubacteria Zymomonas mobilis (Z. mobilis TGT) and Escherichia coli (E. coli TGT) show a different behaviour in the presence of competitive inhibitors. The active sites of both enzymes are identical apart from a single conservative amino acid exchange, namely Tyr106 of Z. mobilis TGT is replaced by a Phe in E. coli TGT. Although Tyr106 is, in contrast to Phe106, hydrogen bonded in the ligand-free structure, we can show by a mutational study of TGT(Y106F) that this is not the reason for the different responses upon competition. The TGT enzymes of various species differ in their substrate selectivity. Depending on the applied pH conditions and/or induced by ligand binding, a peptide-bond flip modulates the recognition properties of the substrate binding site, which changes between donor and acceptor functionality. Furthermore interstitial water molecules play an important role in these adaptations of the pocket. The flip of the peptide bond is further stabilised by a glutamate residue that operates as general acid/base. An active-site aspartate residue, presumed to operate as a nucleophile through covalent bonding during the base-exchange reaction, shows different conformations depending on the nature of the bound ligand. The induced-fit adaptations observed in the various TGT complex structures by multiple crystal-structure analyses are in agreement with the functional properties of the enzyme. In consequence, full understanding of this plasticity can be exploited for drug design.

Literature references that cite this PDB file's key reference

  PubMed id Reference
19894214 T.Ritschel, P.C.Kohler, G.Neudert, A.Heine, F.Diederich, and G.Klebe (2009).
How to Replace the Residual Solvation Shell of Polar Active Site Residues to Achieve Nanomolar Inhibition of tRNA-Guanine Transglycosylase.
  ChemMedChem, 4, 2012-2023.
PDB codes: 3eos 3eou 3gc4 3gc5 3ge7
17803682 I.Pérez-Arellano, J.Gallego, and J.Cervera (2007).
The PUA domain - a structural and functional overview.
  FEBS J, 274, 4972-4984.  
17949745 N.Tidten, B.Stengl, A.Heine, G.A.Garcia, G.Klebe, and K.Reuter (2007).
Glutamate versus glutamine exchange swaps substrate selectivity in tRNA-guanine transglycosylase: insight into the regulation of substrate selectivity by kinetic and crystallographic studies.
  J Mol Biol, 374, 764-776.
PDB codes: 2oko 2pot 2pwu 2pwv 2qii 2z1v 2z1w 2z1x
16206323 B.Stengl, K.Reuter, and G.Klebe (2005).
Mechanism and substrate specificity of tRNA-guanine transglycosylases (TGTs): tRNA-modifying enzymes from the three different kingdoms of life share a common catalytic mechanism.
  Chembiochem, 6, 1926-1939.  
15951383 K.A.Todorov, X.J.Tan, S.T.Nonekowski, G.A.Garcia, and H.A.Carlson (2005).
The role of aspartic acid 143 in E. coli tRNA-guanine transglycosylase: insights from mutagenesis studies and computational modeling.
  Biophys J, 89, 1965-1977.  
The most recent references are shown first. Citation data come partly from CiteXplore and partly from an automated harvesting procedure. Note that this is likely to be only a partial list as not all journals are covered by either method. However, we are continually building up the citation data so more and more references will be included with time. Where a reference describes a PDB structure, the PDB codes are shown on the right.