Repeat

Pentatricopeptide repeat (IPR002885)

Short name: Pentatricopeptide_repeat

Description

This entry represents the PPR repeat.

Pentatricopeptide repeat (PPR) proteins are characterised by tandem repeats of a degenerate 35 amino acid motif [PMID: 10664580]. PPR proteins are sequence-specific RNA-binding proteins that are involved in multiple aspects of RNA metabolism [PMID: 18031283, PMID: 22576772]. Most have roles in mitochondria or plastids [PMID: 15270678]. PPR repeats were discovered while screening Arabidopsis proteins for those predicted to be targeted to mitochondria or chloroplast [PMID: 10664580, PMID: 15269332]. Some of these proteins have been shown to play a role in post-transcriptional processes within organelles [PMID: 12782738, PMID: 12832482]. Plant genomes have between one hundred to five hundred PPR genes per genome whereas non-plant genomes encode two to six PPR proteins.

The plant PPR protein family has been divided in two subfamilies on the basis of their motif content and organisation [PMID: 15269332, PMID: 17560114].

The crystal structure of maize chloroplast PPR10 has been reported. The nineteen repeats of PPR10 are assembled into a right-handed superhelical spiral. PPR10 forms a homodimer and exhibits considerable conformational changes upon binding to its ssRNA target, with six nucleotides being specifically recognized by six corresponding PPR10 repeats [PMID: 24162847].

Contributing signatures

Signatures from InterPro member databases are used to construct an entry.
Pfam
PROSITE profiles
Pfam
Pfam
TIGRFAMs
Pfam