title: From end to end: tRNA editing at 5'- and 3'-terminal positions.
abstract: During maturation, tRNA molecules undergo a series of individual processing steps, ranging from exo- and endonucleolytic trimming reactions at their 5'- and 3'-ends, specific base modifications and intron removal to the addition of the conserved 3'-terminal CCA sequence. Especially in mitochondria, this plethora of processing steps is completed by various editing events, where base identities at internal positions are changed and/or nucleotides at 5'- and 3'-ends are replaced or incorporated. In this review, we will focus predominantly on the latter reactions, where a growing number of cases indicate that these editing events represent a rather frequent and widespread phenomenon. While the mechanistic basis for 5'- and 3'-end editing differs dramatically, both reactions represent an absolute requirement for generating a functional tRNA. Current in vivo and in vitro model systems support a scenario in which these highly specific maturation reactions might have evolved out of ancient promiscuous RNA polymerization or quality control systems.
authors.affiliation: Institute for Biochemistry, University of Leipzig, Brüderstraße 34, 04103 Leipzig, Germany. heike.betat@uni-leipzig.de.
authors.forename: Heike
authors.initials: H
authors.lastname: Betat
authors.affiliation: Department of Chemistry and Biochemistry, Center for RNA Biology and Ohio State Biochemistry Program, the Ohio State University, Columbus, OH 43210, USA. long.918@osu.edu.
authors.forename: Yicheng
authors.initials: Y
authors.lastname: Long
authors.affiliation: Department of Chemistry and Biochemistry, Center for RNA Biology and Ohio State Biochemistry Program, the Ohio State University, Columbus, OH 43210, USA. jackman.14@osu.edu.
authors.forename: Jane E
authors.initials: JE
authors.lastname: Jackman
authors.affiliation: Institute for Biochemistry, University of Leipzig, Brüderstraße 34, 04103 Leipzig, Germany. mario.moerl@uni-leipzig.de.
authors.forename: Mario
authors.initials: M
authors.lastname: Mörl
mesh_terms: D000818:Animals; D005075:Biological Evolution; D006801:Humans; D017393:RNA Editing; D012343:RNA, Transfer / Q000235:genetics* / Q000378:metabolism*; D012441:Saccharomyces cerevisiae / Q000235:genetics / Q000378:metabolism
chemical_list: D012343:RNA, Transfer