The intracellular bacterial pathogen Legionella pneumophila proliferates in human alveolar macrophages， resulting in a severe pneumonia termed Legionnaires' disease. Throughout the course of infection， L. pneumophila remains enclosed in a specialized membrane compartment that evades fusion with lysosomes. The pathogen delivers over 300 effector proteins into the host cell， altering host pathways in a manner that sets the stage for efficient pathogen replication. The L. pneumophila effector protein AnkX targets host Rab GTPases and functions in preventing fusion of the Legionella-containing vacuole with lysosomes. However， the current understanding of AnkX's interaction with host proteins and the means through which it exerts its cellular function is limited.