Structure-based mechanistic insights into catalysis by tRNA thiolation enzymes
Related Experiment Video
Updated: Dec 15, 2025

DNA-Tethered RNA Polymerase for Programmable In vitro Transcription and Molecular Computation
Published on: December 29, 2021
Ornella Bimai1, Simon Arragain1, Béatrice Golinelli-Pimpaneau1
1Laboratoire de Chimie des Processus Biologiques, UMR 8229 CNRS, Collège de France, Université Paris Sciences et Lettres, 11 Place Marcelin Berthelot, 75231 Paris cedex 05, France.
Abstract:
In all domains of life, ribonucleic acid (RNA) maturation includes post-transcriptional chemical modifications of nucleosides. Many sulfur-containing nucleosides have been identified in transfer RNAs (tRNAs), such as the derivatives of 2-thiouridine (s2U), 4-thiouridine (s4U), 2-thiocytidine (s2C), 2-methylthioadenosine (ms2A). These modifications are essential for accurate and efficient translation of the genetic code from messenger RNA (mRNA) for protein synthesis. This review summarizes the recent discoveries concerning the mechanistic and structural characterization of tRNA thiolation enzymes that catalyze the non-redox substitution of oxygen for sulfur in nucleosides. Two mechanisms have been described. One involves persulfide formation on catalytic cysteines, while the other uses a [4Fe-4S] cluster, chelated by three conserved cysteines only, as a sulfur carrier.
Related Concept Videos
Introduction to Mechanisms of Enzyme Catalysis
tRNA Activation
tRNA Activation
Transfer RNA Synthesis
Each of these chemical modifications is carried by a specific enzyme, post-transcription. All of these enzymes have unique base and site-specificity. Methylation, the most common chemical modification, is carried by at least nine different enzymes, with...
Induced-fit Model
Enzymes exhibit substrate specificity, meaning that they can only bind to certain substrates. This is mainly determined by the shape and chemical...
RNA Structure
Different Types of RNA Have the Same Basic Structure
There are three main types of ribonucleic acid (RNA) involved in protein synthesis: messenger RNA (mRNA), transfer RNA (tRNA), and ribosomal RNA (rRNA). All three...

