C1
Due to a paucity of initial hits (17 total genera), the genus-level filter was removed for all phyla to increase resolution of the domain phylogeny. A preliminary tree (Fig. S2) was expanded to identify outgroup sequences by including hits with E ≤ 10-10. The resulting tree was rooted using minimal ancestor deviation (MAD) rooting (Tria, Landan and Dagan, 2017).