Mitochondrial tRNA 5′-Editing in Dictyostelium discoideum and Polysphondylium pallidum

• DOI: 10.1074/jbc.m114.561514
• Publication Date: 2014-04-16T03:41:50Z
• Authors: Maria G. Abad; Yicheng Long; R. Dimitri Kinchen; Elinor T. Schindel; Michael W. Gray; Jane E. Jackman
• Keywords: Slime Mold

Mitochondrial tRNA (mt-tRNA) 5'-editing was first described more than 20 years ago; however, the candidates for enzymes were only recently identified in a eukaryotic microbe (protist), slime mold Dictyostelium discoideum. In this organism, eight of 18 mt-tRNAs are predicted to be edited based on presence genomically encoded mismatched nucleotides their aminoacyl-acceptor stem sequences. Here, we demonstrate that mt-tRNA occurs at all sites D. discoideum as evidenced by changes sequences isolated compared with expected mitochondrial genome. We also identify two previously unpredicted editing events which G-U base pairs absence any other mismatches. A comparison another mold, Polysphondylium pallidum, suggests organism-specific idiosyncrasies treatment U-G/G-U pairs. vitro activities putative consistent observed reactions and suggest an overall lack substrate specificity exhibited repair component enzyme. Although terminal mismatches is highly predictive occurrence 5'-editing, variability here indicates direct experimental evidence must obtained understand complete spectrum species.