title: The Architecture of Trypanosoma brucei editosomes.
abstract: Uridine insertion and deletion RNA editing generates functional mitochondrial mRNAs in Trypanosoma brucei Editing is catalyzed by three distinct ∼20S editosomes that have a common set of 12 proteins, but are typified by mutually exclusive RNase III endonucleases with distinct cleavage specificities and unique partner proteins. Previous studies identified a network of protein-protein interactions among a subset of common editosome proteins, but interactions among the endonucleases and their partner proteins, and their interactions with common subunits were not identified. Here, chemical cross-linking and mass spectrometry, comparative structural modeling, and genetic and biochemical analyses were used to define the molecular architecture and subunit organization of purified editosomes. We identified intra- and interprotein cross-links for all editosome subunits that are fully consistent with editosome protein structures and previously identified interactions, which we validated by genetic and biochemical studies. The results were used to create a highly detailed map of editosome protein domain proximities, leading to identification of molecular interactions between subunits, insights into the functions of noncatalytic editosome proteins, and a global understanding of editosome architecture.
authors.affiliation: Center for Infectious Disease Research, Seattle, WA 98109.
authors.forename: Suzanne M
authors.initials: SM
authors.lastname: McDermott
authors.affiliation: Institute for Systems Biology, Seattle, WA 98109.
authors.forename: Jie
authors.initials: J
authors.lastname: Luo
authors.affiliation: Center for Infectious Disease Research, Seattle, WA 98109.
authors.forename: Jason
authors.initials: J
authors.lastname: Carnes
authors.affiliation: Institute for Systems Biology, Seattle, WA 98109 jranish@systemsbiology.org ken.stuart@cidresearch.org.
authors.forename: Jeff A
authors.initials: JA
authors.lastname: Ranish
authors.affiliation: Center for Infectious Disease Research, Seattle, WA 98109; jranish@systemsbiology.org ken.stuart@cidresearch.org.
authors.forename: Kenneth
authors.initials: K
authors.lastname: Stuart
mesh_terms: D019295:Computational Biology / Q000379:methods; D004720:Endonucleases / Q000378:metabolism; D008958:Models, Molecular; D046912:Multiprotein Complexes / Q000378:metabolism; D011485:Protein Binding; D011487:Protein Conformation; D054730:Protein Interaction Domains and Motifs; D060066:Protein Interaction Maps; D020543:Proteome; D040901:Proteomics / Q000379:methods; D015800:Protozoan Proteins / Q000737:chemistry / Q000378:metabolism*; D017393:RNA Editing; D016053:RNA, Protozoan / Q000235:genetics*; D016601:RNA-Binding Proteins / Q000378:metabolism; D015203:Reproducibility of Results; D014346:Trypanosoma brucei brucei / Q000235:genetics* / Q000378:metabolism*
chemical_list: D046912:Multiprotein Complexes; D020543:Proteome; D015800:Protozoan Proteins; D016053:RNA, Protozoan; D016601:RNA-Binding Proteins; D004720:Endonucleases
keywords: RNA editing; Trypanosoma brucei; cross-linking; editosome; proteomics