Legionella pneumophila delivers over 300 effector proteins into the host cytosol. One of these effectors, LubX contains 2 U-box domains, and directs the proeosomal degradation of another translocated protein, SidH, however this 'metaeffector' activity is pooly understood. As part of our investigation of the interaction of LubX and SidH, we idenified a LubX mutant that was no longer able to abrogate the toxicity of ectopically expressed SidH in yeast. This dataset belongs to AP-MS experiments conducted to test the ability of these mutants for their ability to bind directly to SidH in Legionella lysate mixtures