Phylogenetic trees and domain composition of Class V and Class VI/VII SDG proteins. Maximum likelihood phylogenetic trees of class V and class VI/VII SDG predicted proteins from Arabidopsis thaliana (At) and Solanum lycopersicon (Sl). Bootstrap values higher than 50% are shown. The tree is drawn to scale, with branch lengths measured in the number of substitutions per site. N-terminal SRA-YDG (PF02182), Pre-SET, SET and Post-SET are conserved domains of the group I of Class V; N-terminal WIYLD (PF10440), or C2H2 (PF00096) or absence of domain, Pre-SET, SET and Post-SET are conserved domains of the group II of Class V (so-called SUVH-related). Proteins with an interrupted SET domain or SET-related proteins are indicated as Class VI and VII.