title: A protein-protein interaction map of trypanosome ~20S editosomes.
abstract: Mitochondrial mRNA editing in trypanosomatid parasites involves several multiprotein assemblies, including three very similar complexes that contain the key enzymatic editing activities and sediment at ~20S on glycerol gradients. These ~20S editosomes have a common set of 12 proteins, including enzymes for uridylyl (U) removal and addition, 2 RNA ligases, 2 proteins with RNase III-like domains, and 6 proteins with predicted oligonucleotide binding (OB) folds. In addition, each of the 3 distinct ~20S editosomes contains a different RNase III-type endonuclease, 1 of 3 related proteins and, in one case, an additional exonuclease. Here we present a protein-protein interaction map that was obtained through a combination of yeast two-hybrid analysis and subcomplex reconstitution with recombinant protein. This map interlinks ten of the proteins and in several cases localizes the protein region mediating the interaction, which often includes the predicted OB-fold domain. The results indicate that the OB-fold proteins form an extensive protein-protein interaction network that connects the two trimeric subcomplexes that catalyze U removal or addition and RNA ligation. One of these proteins, KREPA6, interacts with the OB-fold zinc finger protein in each subcomplex that interconnects their two catalytic proteins. Another OB-fold protein, KREPA3, appears to link to the putative endonuclease subcomplex. These results reveal a physical organization that underlies the coordination of the various catalytic and substrate binding activities within the ~20S editosomes during the editing process.
authors.affiliation: Seattle Biomedical Research Institute, Seattle, Washington 98109, USA.
authors.forename: Achim
authors.initials: A
authors.lastname: Schnaufer
authors.forename: Meiting
authors.initials: M
authors.lastname: Wu
authors.forename: Young-jun
authors.initials: YJ
authors.lastname: Park
authors.forename: Tadashi
authors.initials: T
authors.lastname: Nakai
authors.forename: Junpeng
authors.initials: J
authors.lastname: Deng
authors.forename: Rose
authors.initials: R
authors.lastname: Proff
authors.forename: Wim G J
authors.initials: WG
authors.lastname: Hol
authors.forename: Kenneth D
authors.initials: KD
authors.lastname: Stuart
mesh_terms: D009097:Multienzyme Complexes / Q000235:genetics / Q000378:metabolism*; D010449:Peptide Mapping; D015800:Protozoan Proteins / Q000235:genetics / Q000378:metabolism*; D012313:RNA / Q000096:biosynthesis / Q000235:genetics; D017393:RNA Editing / Q000502:physiology*; D012333:RNA, Messenger / Q000096:biosynthesis / Q000235:genetics; D000077278:RNA, Mitochondrial; D016053:RNA, Protozoan / Q000096:biosynthesis / Q000235:genetics; D043244:Ribonuclease III / Q000235:genetics / Q000378:metabolism*; D012261:Ribonucleoproteins / Q000235:genetics / Q000378:metabolism*; D014346:Trypanosoma brucei brucei / Q000201:enzymology* / Q000235:genetics
chemical_list: D009097:Multienzyme Complexes; D015800:Protozoan Proteins; D012333:RNA, Messenger; D000077278:RNA, Mitochondrial; D016053:RNA, Protozoan; D012261:Ribonucleoproteins; C437999:TbMP42 protein, Trypanosoma brucei; D012313:RNA; D043244:Ribonuclease III