RNA splicing, via endonucleolytic cleavage and ligation tRNA splicing, via endonucleolytic cleavage and ligation Splicing of tRNA substrates via recognition of the folded RNA structure that brings the 5' and 3' splice sites into proximity and cleavage of the RNA at both the 3' and 5' splice sites by an endonucleolytic mechanism, followed by ligation of the exons. tRNA-Y splicing biological_process GO:0006388 Note that while typically associated with tRNA splicing, splicing via endonucleolytic cleavages and subsequent ligation of the free exon ends is known to be used for some non-tRNA substrates, e.g. HAC1 (YFL031W) in S. cerevisiae and an intron in the 23S rRNA of the Archaeal species Desulfurococcus mobilis. tRNA processing