Percent identity matrix calculated from a PSI-Coffee alignment (Notredame et al, 2000) of the predicted OTU domains. OTUB1 (80-271), EschOTU (184-362), ceg7 (1-298), BurkOTU (186-315), ChlaOTU (193-473), RickOTU (161-356), wPipOTU (66-354), wMelOTU (40-205), and ceg23 (9-277) were used to create the alignment. 