Synthesis and metabolic fate of 4-methylthiouridine in bacterial tRNA.

Synthesis and metabolic fate of 4-methylthiouridine in bacterial tRNA. Chembiochem. 2020 May 12;: Authors: Borek C, Reichle VF, Kellner S Abstract Ribonucleic acid (RNA) is central to many life processes and to fulfil its function it has a substantial chemical variety of its building blocks. Enzymatic thiolation of uridine introduces 4-thiouridine (s4U) into many bacterial transfer RNAs (tRNAs) which is used as a sensor for UV radiation. A similar modified nucleoside, 2-thiocytidine, was recently found to be sulfur-methylated especially in bacteria exposed to antibiotics and simple methylating reagents. Here, we report the synthesis of 4-methylthiouridine (ms4U) and confirm its presence and additional formation under stress in E. coli. We use the synthetic ms4U for isotope dilution mass spectrometry and compare its abundance to other reported tRNA damage products. In addition, we apply sophisticated stable isotope pulse chase studies (NAIL-MS) and show its AlkB independent removal in vivo. Our findings reveal the complex nature of bacterial RNA damage repair. PMID: 32394608 [PubMed - as supplied by publisher]
Source: Chembiochem - Category: Biochemistry Authors: Tags: Chembiochem Source Type: research