The pentatricopeptide repeat (PPR) is a 35-amino acid sequence motif. Pentatricopeptide-repeat-containing proteins are a family of proteins commonly found in the plant kingdom. They are distinguished by the presence of tandem degenerate PPR motifs[1] and by the relative lack of introns in the genes coding for them.[2]
| Pentatricopeptide repeat | |||||||||
|---|---|---|---|---|---|---|---|---|---|
| Identifiers | |||||||||
| Symbol | PPR | ||||||||
| Pfam | PF01535 | ||||||||
| Pfam clan | CL0020 | ||||||||
| InterPro | IPR002885 | ||||||||
| PROSITE | PS51375 | ||||||||
| |||||||||
Approximately 450 such proteins have been identified in the Arabidopsis genome, and another 477 in the rice genome.[3] Despite the large size of the protein family, genetic data suggest that there is little or no redundancy of function between the PPR proteins in Arabidopsis.[2]
The purpose of PPR proteins is currently under dispute. It has been shown that a good deal of those in Arabidopsis interact (often essentially) with mitochondria and other organelles[2] and that they are possibly involved in RNA editing.[4] However many trans proteins are required for this editing to occur and research continues to look at which proteins are needed.[5]
The structure of the PPR has been resolved. It folds into a helix-turn-helix structure similar to those found in the tetratricopeptide repeat. Several repeats of the protein forms a ring around a single-strand RNA molecule in a sequence-sensitive way reminiscent of TAL effectors.[6]
Examples
editHuman genes encoding proteins containing this repeat include:
References
edit- ^ Mingler MK, Hingst AM, Clement SL, Yu LE, Reifur L, Koslowsky DJ (November 2006). "Identification of pentatricopeptide repeat proteins in Trypanosoma brucei". Mol. Biochem. Parasitol. 150 (1): 37–45. doi:10.1016/j.molbiopara.2006.06.006. PMID 16837079.
- ^ a b c Lurin C, Andrés C, Aubourg S, Bellaoui M, Bitton F, Bruyère C, Caboche M, Debast C, Gualberto J, Hoffmann B, Lecharny A, Le Ret M, Martin-Magniette ML, Mireau H, Peeters N, Renou JP, Szurek B, Taconnat L, Small I (August 2004). "Genome-wide analysis of Arabidopsis pentatricopeptide repeat proteins reveals their essential role in organelle biogenesis". Plant Cell. 16 (8): 2089–103. doi:10.1105/tpc.104.022236. PMC 519200. PMID 15269332.
- ^ O'Toole N, Hattori M, Andres C, Iida K, Lurin C, Schmitz-Linneweber C, Sugita M, Small I (June 2008). "On the expansion of the pentatricopeptide repeat gene family in plants". Mol. Biol. Evol. 25 (6): 1120–8. doi:10.1093/molbev/msn057. PMID 18343892.
- ^ Kotera E, Tasaka M, Shikanai T (January 2005). "A pentatricopeptide repeat protein is essential for RNA editing in chloroplasts". Nature. 433 (7023): 326–30. Bibcode:2005Natur.433..326K. doi:10.1038/nature03229. PMID 15662426. S2CID 4416316.
- ^ Takenaka M, Verbitskiy D, Zehrmann A, Brennicke A (June 2010). "Reverse genetic screening identifies five E-class PPR-proteins involved in RNA editing in mitochondria of Arabidopsis Thaliana". J Biol Chem. 285 (35): 27122–27129. doi:10.1074/jbc.M110.128611. PMC 2930711. PMID 20566637.
- ^ Yin P, Li Q, Yan C, Liu Y, Liu J, Yu F, et al. (December 2013). "Structural basis for the modular recognition of single-stranded RNA by PPR proteins". Nature. 504 (7478): 168–71. Bibcode:2013Natur.504..168Y. doi:10.1038/nature12651. PMID 24162847. S2CID 4471801.
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