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Recycling factors for ribosome disassembly in the apicoplast and mitochondrion of P lasmodium falciparum
Author(s) -
Gupta Ankit,
Mir Snober S.,
Jackson Katherine E.,
Lim Erin E.,
Shah Priyanka,
Sinha Ashima,
Siddiqi Mohammad Imran,
Ralph Stuart A.,
Habib Saman
Publication year - 2013
Publication title -
molecular microbiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.857
H-Index - 247
eISSN - 1365-2958
pISSN - 0950-382X
DOI - 10.1111/mmi.12230
Subject(s) - apicoplast , biology , mitochondrion , ribosome , plastid , computational biology , biochemistry , microbiology and biotechnology , rna , chloroplast , gene
Summary The reduced genomes of the apicoplast and mitochondrion of the malaria parasite P lasmodium falciparum are actively translated and antibiotic‐mediated translation inhibition is detrimental to parasite survival. In order to understand recycling of organellar ribosomes, a critical step in protein translation, we identified ribosome recycling factors ( RRF ) encoded by the parasite nuclear genome. Targeting of Pf RRF1 and Pf RRF2 to the apicoplast and mitochondrion respectively was established by localization of leader sequence– GFP fusions. Unlike any RRF characterized thus far, Pf RRF2 formed dimers with disulphide interaction(s) and additionally localized in the cytoplasm, thus suggesting adjunct functions for the factor. Pf RRF1 carries a large 108‐amino‐acid insertion in the functionally critical hinge region between the head and tail domains of the protein, yet complemented E scherichia coli RRF in the LJ14 frr ts mutant and disassembled surrogate E . coli 70 S ribosomes in the presence of apicoplast‐targeted EF ‐ G . Recombinant Pf RRF2 bound E . coli ribosomes and could split monosomes in the presence of the relevant mitochondrial EF ‐ G but failed to complement the LJ14 frr ts mutant. Although proteins comprising subunits of P . falciparum organellar ribosomes are predicted to differ from bacterial and mitoribosomal counterparts, our results indicate that the essential interactions required for recycling are conserved in parasite organelles.