This repeat has no known function. It is about 35 amino acids long and is found in up to 18 copies in some proteins. The family appears to be greatly expanded in plants and fungi. The repeat has been called PPR [1].

1: The PPR motif - a TPR-related motif prevalent in plant organellar proteins. Small ID, Peeters I; Trends Biochem Sci 2000;25:45-47. PMID:10664580