TbMP57 is a 3' terminal uridylyl transferase (TUTase) of the Trypanosoma brucei editosome.
RNA editing produces mature trypanosome mitochondrial mRNAs by uridylate (U) insertion and deletion. In insertion editing, Us are added to the pre-mRNA by a 3' terminal uridylyl transferase (TUTase) activity. We report the identification of a TUTase activity that copurifies with in vitro editing and is catalyzed by the integral editosome protein TbMP57. TbMP57 catalyzes the addition of primarily a single U to single-stranded (ss) RNA and adds the number of Us specified by a guide RNA to insertion editing-like substrates. TbMP57 is distinct from a previously identified TUTase that adds many Us to ssRNA and which we find is neither a stable editosome component nor does it add Us to editing-like substrates. Recombinant TbMP57 specifically interacts with the editosome protein TbMP81, and this interaction enhances the TUTase activity. These results suggest that TbMP57 catalyzes U addition to pre-mRNA during editing.
Ernst
Nancy Lewis
NL
Seattle Biomedical Research Institute, Seattle, WA 98109, USA.
Panicucci
Brian
B
Igo
Robert P
RP
Panigrahi
Aswini K
AK
Salavati
Reza
R
Stuart
Kenneth
K
D000818:Animals; D002384:Catalysis; D002847:Chromatography, Agarose; D002850:Chromatography, Gel; D002852:Chromatography, Ion Exchange; D008928:Mitochondria / Q000737:chemistry / Q000201:enzymology*; D008969:Molecular Sequence Data; D008970:Molecular Weight; D017434:Protein Structure, Tertiary; D015800:Protozoan Proteins; D012313:RNA / Q000235:genetics / Q000378:metabolism; D017393:RNA Editing; D012322:RNA Precursors / Q000235:genetics / Q000378:metabolism; D017394:RNA, Guide, Kinetoplastida / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D011994:Recombinant Proteins / Q000378:metabolism; D012261:Ribonucleoproteins / Q000378:metabolism; D013379:Substrate Specificity; D014346:Trypanosoma brucei brucei / Q000166:cytology / Q000201:enzymology* / Q000235:genetics; D006599:UDPglucose-Hexose-1-Phosphate Uridylyltransferase / Q000235:genetics / Q000302:isolation & purification* / Q000378:metabolism*
D015800:Protozoan Proteins; D012322:RNA Precursors; D012333:RNA, Messenger; D011994:Recombinant Proteins; D012261:Ribonucleoproteins; C437997:TbMP81 protein, Trypanosoma brucei; D012313:RNA; D006599:UDPglucose-Hexose-1-Phosphate Uridylyltransferase; D017394:RNA, Guide, Kinetoplastida