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PPR-SMRs: Ancient proteins with enigmatic functions
RNA Biology (2013)
  • Sheng Liu, The University of Western Australia
  • Joanna Melonek, The University of Western Australia
  • Laura M Boykin, The University of Western Australia
  • Ian Small, The University of Western Australia
  • Kate Howell, The University of Notre Dame Australia
Abstract
A small subset of the large pentatricopeptide repeat (PPR)
protein family in higher plants contain a C-terminal small MutSrelated
(SMR) domain. Although few in number, they figure
prominently in the chloroplast biogenesis and retrograde
signaling literature due to their striking mutant phenotypes.
In this review, we summarize current knowledge of PPRSMR
proteins focusing on Arabidopsis and maize proteomic
and mutant studies. We also examine their occurrence in
other organisms and have determined by phylogenetic
analysis that, while they are limited to species that contain
chloroplasts, their presence in algae and early branching land
plant lineages indicates that the coupling of PPR motifs and
an SMR domain into a single protein occurred early in the
evolution of the Viridiplantae clade. In addition, we discuss
their possible function and have examined conservation
between SMR domains from Arabidopsis PPR proteins with
those from other species that have been shown to possess
endonucleolytic activity.
Disciplines
Publication Date
2013
DOI
10.4161/rna.26172
Citation Information
PPR-SMRs: Ancient proteins with enigmatic functions. RNA Biol 10(9): 1501