Many Gram-negative bacteria modulate host immune responses through the activity of effector proteins delivered by secretion systems. The downstream changes mediated by an effector's enzymatic activity ranges from the highly specific, to the multifunctional and often this represents unusual biochemistry. Together, the combined action of a bacteria’s effector repertoire impacts the function of an impressive array of host cellular processes, including signal transduction and the manipulation of innate immune responses. Here, I will present in mechanistic detail how the intracellular bacterium, Burkholderia, reverses a host post-translational modification, to counteract the immune response of the infected cell.