Lpg0393 is a Legionella pneumophila effector protein. Structure analysis reveals that it has two domains, the N-terminal domain is a Vps9-like domain, which is structurally most similar to the catalytic core of human Rabex-5 that activates the endosomal Rab proteins Rab5, Rab21 and Rab22. The C-terminal domain is a helical bundle domain. The C-terminal helical bundle of Lpg0393 corresponds to the N-terminal helical bundle of Rabex-5, it lacks an obvious region that corresponds to the membrane-binding motif of Rabex-5. One possibility may be that Lpg0393 localization to endosomes depends on an unknown Legionella effector [1].

1: Lpg0393 of Legionella pneumophila is a guanine-nucleotide exchange factor for Rab5, Rab21 and Rab22. Sohn YS, Shin HC, Park WS, Ge J, Kim CH, Lee BL, Heo WD, Jung JU, Rigden DJ, Oh BH; PLoS One. 2015;10:e0118683. PMID:25821953