Figure 4.

Proposed infection model of the E. montiporae. When E. montiporae attaches to the host mucus layer, secreted Endo-A_EMO could reduce mucus viscosity, enabling the bacterium to penetrate through the mucus (1). Once the bacterium reached the host plasma membrane, the EfnB2_2 could bind with host Eph receptors (2), and initiate endocytosis (3). When E. montiporae enters into a host cell, it might use extracellular enzymes to disrupt the endosome and interfere with phagolysosome maturation by chelating Rabs with EZMO1_3398 (4). After escaping the endosome, E. montiporae could utilize nutrients in the host cytoplasm, particularly glucose produced by endosymbiotic zooxanthellae (5).