Phylogenetic trees and domain composition of Class III and Class IV SDG proteins. Maximum likelihood phylogenetic trees of Class III (A) and Class IV (B) 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 PWWP (PF00855), FYRN (PF05964), FYRC (PF05965), two PHD, SET, and Post-SET are conserved domains of Class III. Some Class III proteins lack the FYRN (PF05964) and FYRC (PF05965) domains. Other Class III have N-terminal GYF (PF02213), SET and Post-SET domains. N-terminal PHD and C-terminal SET are conserved domains of Class IV.