Bimai Ornella, Arragain Simon, Golinelli-Pimpaneau Béatrice
Laboratoire 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.
Laboratoire 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.
Curr Opin Struct Biol. 2020 Dec;65:69-78. doi: 10.1016/j.sbi.2020.06.002. Epub 2020 Jul 8.
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 (sU), 4-thiouridine (sU), 2-thiocytidine (sC), 2-methylthioadenosine (msA). 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.
在生命的所有领域中，核糖核酸（RNA）成熟过程包括核苷的转录后化学修饰。在转运RNA（tRNA）中已鉴定出许多含硫核苷，例如2-硫代尿苷（sU）、4-硫代尿苷（sU）、2-硫代胞苷（sC）、2-甲硫腺苷（msA）的衍生物。这些修饰对于从信使RNA（mRNA）准确有效地翻译遗传密码以进行蛋白质合成至关重要。本综述总结了关于催化核苷中氧被硫进行非氧化还原取代的tRNA硫醇化酶的机制和结构特征的最新发现。已描述了两种机制。一种涉及催化半胱氨酸上形成过硫化物，而另一种则使用仅由三个保守半胱氨酸螯合的[4Fe-4S]簇作为硫载体。
