Structures of the T. brucei kRNA editing factor MRB1590 reveal unique RNA-binding pore motif contained within an ABC-ATPase fold.

Published

Journal Article

Kinetoplastid RNA (kRNA) editing is a process that creates translatable mitochondrial mRNA transcripts from cryptogene encoded RNAs and is unique for kinetoplastids, such as Trypanosoma brucei. In addition to the catalytic 20S editosome, multiple accessory proteins are required for this conversion. Recently, the multiprotein mitochondrial RNA binding complex 1 (MRB1) has emerged as a key player in this process. MRB1 consists of six core proteins but makes dynamic interactions with additional accessory proteins. Here we describe the characterization of one such factor, the 72 kDa MRB1590 protein. In vivo experiments indicate a role for MRB1590 in editing mitochondrial mRNA transcripts, in particular the transcript encoding the ATP synthase subunit 6 (A6). Structural studies show that MRB1590 is dimeric and contains a central ABC-ATPase fold embedded between novel N- and C-terminal regions. The N-terminal domains combine to create a basic pore and biochemical studies indicate residues in this region participate in RNA binding. Structures capturing distinct MRB1590 conformations reveal that the RNA binding pore adopts closed and open states, with the latter able to accommodate RNA. Based on these findings, implications for MRB1590 function are discussed.

Full Text

Duke Authors

Cited Authors

  • Shaw, PLR; McAdams, NM; Hast, MA; Ammerman, ML; Read, LK; Schumacher, MA

Published Date

  • August 2015

Published In

Volume / Issue

  • 43 / 14

Start / End Page

  • 7096 - 7109

PubMed ID

  • 26117548

Pubmed Central ID

  • 26117548

Electronic International Standard Serial Number (EISSN)

  • 1362-4962

International Standard Serial Number (ISSN)

  • 0305-1048

Digital Object Identifier (DOI)

  • 10.1093/nar/gkv647

Language

  • eng