Transfer RNA (tRNA) is a canonical translator that delivers the designated amino acid to ribosomes for protein synthesis. However, recent discoveries have revealed that the tRNA-derived RNA (tdR), a fragment of tRNA previously considered debris during tRNA degradation, has multiple novel roles in regulating translation, post-transcriptional modification, and transcription. These functions are essential steps in cell physiology, thereby highlighting the importance of tdR biogenesis. Notably, the biogenesis of nicked-tRNA, a major type of the tdR, involves tRNA nickase, such as angiogenin, and nicked-tRNA helicase, which has not been discovered. In this study, we tested the unwinding activity of a newly identified potential nicked-tRNA helicase (ntHel) through a single-molecule approach. We investigated the selective nicked-tRNA unwinding activity of ntHel in the presence of ATP. The discovery of ntHel will shed light on the regulation of nicked-tRNA levels in cells and the pathogenesis of tdR-related disease.
Cho et al. (Sun,) studied this question.