T. brucei RNA editing: adenosine nucleotides inversely affect U-deletion and U-insertion reactions at mRNA cleavage.
In the currently envisioned mechanism of trypanosome mitochondrial RNA editing, U-insertion and U-deletion cycles begin with a common kind of gRNA-directed cleavage. However, natural, altered, and mutationally interconverted editing sites reveal that U-deletional cleavage is inefficient without and activated by ATP and ADP, while U-insertional cleavage shows completely reverse nucleotide effects. The adenosine nucleotides' effects appear to be allosteric and determined solely by sequences immediately adjacent to the anchor duplex. Both U-deletional and U-insertional cleavages are reasonably active at physiological mitochondrial ATP concentration. Notably, ATP and ADP markedly stimulate complete U-deletion and inhibit U-insertion reactions, reflecting their effects on cleavage. These plus previous results suggest that U deletion and U insertion are remarkably distinct.
Cruz-Reyes
J
J
Department of Biological Chemistry, Johns Hopkins University School of Medicine, Baltimore, Maryland 21205, USA.
Rusché
L N
LN
Piller
K J
KJ
Sollner-Webb
B
B
D000241:Adenosine / Q000235:genetics*; D000244:Adenosine Diphosphate / Q000494:pharmacology; D000255:Adenosine Triphosphate / Q000494:pharmacology; D000818:Animals; D001483:Base Sequence; D003573:Cytochrome b Group / Q000235:genetics; D004720:Endonucleases / Q000378:metabolism; D016297:Mutagenesis, Site-Directed; D017393:RNA Editing / Q000187:drug effects / Q000502:physiology*; D011130:RNA Ligase (ATP) / Q000378:metabolism; D012316:RNA Nucleotidyltransferases / Q000378:metabolism; D012322:RNA Precursors / Q000378:metabolism*; D016053:RNA, Protozoan / Q000378:metabolism; D014346:Trypanosoma brucei brucei / Q000201:enzymology / Q000235:genetics*
D003573:Cytochrome b Group; D012322:RNA Precursors; D016053:RNA, Protozoan; D000244:Adenosine Diphosphate; D000255:Adenosine Triphosphate; D012316:RNA Nucleotidyltransferases; C031687:UTP-RNA uridylyltransferase; D004720:Endonucleases; D011130:RNA Ligase (ATP); D000241:Adenosine