Figure 2. Sub-tree extracted from the phylogenetic tree of PPR proteins computed from average inter-repeat distances, showing the relationship between the MT4-domain containing PPR19 and PPR26, and the relationship to PPR20 and PPR1/HCF152. PPR repeats are indicated by red boxes, Methyltransferase_4 domains by blue boxes, Zn-finger CCCH domains in PPR19 by white dots.