Effector that interferes with the host cell ubiquitin pathway and is required for intracellular bacterial replication. Catalyzes the ubiquitination of several host Rab small GTPases associated with the endoplasmic reticulum during L.pneumophila infection, without engaging the standard cellular enzyme cascade (E1 and E2) (PubMed:27049943). Transfers an ADP-ribose moiety from NAD to the 'Arg-42' residue of ubiquitin in a reaction that releases nicotinamide (PubMed:27049943, PubMed:29731171). The modified ubiquitin is subsequently transferred to serine residues of the substrate protein via a phosphoribose linker that results in the release of AMP (PubMed:27912065). L-arginyl-[protein] + NAD(+) = H(+) + N(omega)-(ADP-D-ribosyl)-L-arginyl-[protein] + nicotinamide Homodimer. Glutamylated by SidJ; glutamylation inhibits sidE activity to catalyze the production of ADP-ribosylated ubiquitin. Cells lacking all four members of the SidE family (SdeA, SdeB, SdeC and SidE) show no intracellular growth defect in mouse bone marrow macrophages (BMM), but display attenuated growth inside the protozoan hosts A.castellanii and D.discoideum. This mutant no longer recruits the endoplasmic reticulum (ER) marker GFP-HDEL to its vacuoles, even at 10 hours post infection, and is unable to induce RAB33B ubiquitination during infection. Belongs to the SidE family. Extended N-terminus.