5MPY

Crystal structure of Arabidopsis thaliana RNA editing factor MORF9

Summary for 5MPY

• Entry DOI: 10.2210/pdb5mpy/pdb
• Descriptor: Multiple organellar RNA editing factor 9, chloroplastic, CALCIUM ION (3 entities in total)
• Functional Keywords: nfld-related fold, plant protein
• Biological source: Arabidopsis thaliana (Thale cress)
• Cellular location: Plastid, chloroplast : Q9LPZ1
• Total number of polymer chains: 2
• Total formula weight: 23232.23

Authors

Haag, S.,Schindler, M.,Berndt, L.,Brennicke, A.,Takenaka, M.,Weber, G. (deposition date: 2016-12-19, release date: 2017-02-22, Last modification date: 2024-01-17)

Primary citation

Haag, S.,Schindler, M.,Berndt, L.,Brennicke, A.,Takenaka, M.,Weber, G.
Crystal structures of the Arabidopsis thaliana organellar RNA editing factors MORF1 and MORF9.
Nucleic Acids Res., 45:4915-4928, 2017

PubMed Abstract: In flowering plant plastids and mitochondria, multiple organellar RNA editing factor (MORF/RIP) proteins are required at most sites for efficient C to U RNA editing catalyzed by the RNA editosome. MORF proteins harbor a conserved stretch of residues (MORF-box), form homo- and heteromers and interact with selected PPR (pentatricopeptide repeat) proteins, which recognize each editing site. The molecular function of the MORF-box remains elusive since it shares no sequence similarity with known domains. We determined structures of the A. thaliana mitochondrial MORF1 and chloroplast MORF9 MORF-boxes which both adopt a novel globular fold (MORF domain). Our structures state a paradigmatic model for MORF domains and their specific dimerization via a hydrophobic interface. We cross-validate the interface by yeast two-hybrid studies and pulldown assays employing structure-based mutants. We find a structural similarity of the MORF domain to an N-terminal ferredoxin-like domain (NFLD), which confers RNA substrate positioning in bacterial 4-thio-uracil tRNA synthetases, implying direct RNA contacts of MORF proteins during RNA editing. With the MORF1 and MORF9 structures we elucidate a yet unknown fold, corroborate MORF interaction studies, validate the mechanism of MORF multimerization by structure-based mutants and pave the way towards a complete structural characterization of the plant RNA editosome.

PubMed: 28201607
DOI: 10.1093/nar/gkx099

Experimental method

X-RAY DIFFRACTION (2.247 Å)