7APL

tRNA-guanine transglycosylase G87C mutant spin-labeled with MTSL

Summary for 7APL

• Entry DOI: 10.2210/pdb7apl/pdb
• Descriptor: Queuine tRNA-ribosyltransferase, ZINC ION, GLYCEROL, ... (4 entities in total)
• Functional Keywords: enzyme, spin label, transferase
• Biological source: Zymomonas mobilis subsp. mobilis (strain ATCC 31821 / ZM4 / CP4)
• Total number of polymer chains: 1
• Total formula weight: 43517.67

Authors

Nguyen, D.,Heine, A.,Klebe, G. (deposition date: 2020-10-18, release date: 2020-10-28, Last modification date: 2024-01-31)

Primary citation

Nguyen, D.,Abdullin, D.,Heubach, C.A.,Pfaffeneder, T.,Nguyen, A.,Heine, A.,Reuter, K.,Diederich, F.,Schiemann, O.,Klebe, G.
Unraveling a Ligand-Induced Twist of a Homodimeric Enzyme by Pulsed Electron-Electron Double Resonance.
Angew.Chem.Int.Ed.Engl., 60:23419-23426, 2021

PubMed Abstract: Mechanistic insights into protein-ligand interactions can yield chemical tools for modulating protein function and enable their use for therapeutic purposes. For the homodimeric enzyme tRNA-guanine transglycosylase (TGT), a putative virulence target of shigellosis, ligand binding has been shown by crystallography to transform the functional dimer geometry into an incompetent twisted one. However, crystallographic observation of both end states does neither verify the ligand-induced transformation of one dimer into the other in solution nor does it shed light on the underlying transformation mechanism. We addressed these questions in an approach that combines site-directed spin labeling (SDSL) with distance measurements based on pulsed electron-electron double resonance (PELDOR or DEER) spectroscopy. We observed an equilibrium between the functional and twisted dimer that depends on the type of ligand, with a pyranose-substituted ligand being the most potent one in shifting the equilibrium toward the twisted dimer. Our experiments suggest a dissociation-association mechanism for the formation of the twisted dimer upon ligand binding.

PubMed: 34387025
DOI: 10.1002/anie.202108179

Experimental method

X-RAY DIFFRACTION (1.99 Å)