The final cut. The importance of tRNA 3'-processing.
To generate functional tRNA molecules, precursor RNAs must undergo several processing steps. While the enzyme that generates the mature tRNA 5'-end, RNase P, has been thoroughly investigated, the 3'-processing activity is, despite its importance, less understood. While nothing is known about tRNA 3'-processing in archaea, the phenomenon has been analysed in detail in bacteria and is known to be a multistep process involving several enzymes, including both exo- and endonucleases. tRNA 3'-end processing in the eukaryotic nucleus seems to be either exonucleolytic or endonucleolytic, depending on the organism analysed, whereas in organelles, 3'-end maturation occurs via a single endonucleolytic cut. An interesting feature of organellar tRNA 3'-processing is the occurrence of overlapping tRNA genes in metazoan mitochondria, which presents a unique challenge for the mitochondrial tRNA maturation enzymes, since it requires not only the removal but also the addition of nucleotides by an editing reaction.
Max-Planck-Institute for Evolutionary Anthropology, Leipzig, Germany.
M
M
Mörl
A
A
Marchfelder
D000818:Animals; D001105:Archaea / Q000378:metabolism; D004722:Endoribonucleases / Q000378:metabolism; D004926:Escherichia coli / Q000378:metabolism; D029968:Escherichia coli Proteins; D008954:Models, Biological; D010944:Plants / Q000378:metabolism; D012323:RNA Processing, Post-Transcriptional; D016337:RNA, Catalytic / Q000378:metabolism; D012343:RNA, Transfer / Q000502:physiology*; D043262:Ribonuclease P; D013045:Species Specificity
D029968:Escherichia coli Proteins; D016337:RNA, Catalytic; D012343:RNA, Transfer; D004722:Endoribonucleases; D043262:Ribonuclease P; C470865:ribonuclease P, E coli