Institute of Biochemistry II, Faculty of Medicine, Goethe University Frankfurt, Frankfurt, Germany; Buchmann Institute for Molecular Life Sciences, Goethe University Frankfurt, Frankfurt, Germany; Max Planck Institute of Biophysics, Frankfurt, Germany; Department of Nano-Bioengineering, Incheon National University, Incheon, Republic of Korea
Institute of Biochemistry II, Faculty of Medicine, Goethe University Frankfurt, Frankfurt, Germany; Buchmann Institute for Molecular Life Sciences, Goethe University Frankfurt, Frankfurt, Germany
Institute of Biochemistry II, Faculty of Medicine, Goethe University Frankfurt, Frankfurt, Germany; Buchmann Institute for Molecular Life Sciences, Goethe University Frankfurt, Frankfurt, Germany
Marta Campos Alonso
Buchmann Institute for Molecular Life Sciences, Goethe University Frankfurt, Frankfurt, Germany
Ahmad Reza Mehdipour
Max Planck Institute of Biophysics, Frankfurt, Germany
Gerbrand J van der Heden van Noort
Oncode Institute and Department of Cell and Chemical Biology, Leiden University Medical Centre, Leiden, Netherlands
Huib Ovaa
Oncode Institute and Department of Cell and Chemical Biology, Leiden University Medical Centre, Leiden, Netherlands
Institute of Biochemistry II, Faculty of Medicine, Goethe University Frankfurt, Frankfurt, Germany; Buchmann Institute for Molecular Life Sciences, Goethe University Frankfurt, Frankfurt, Germany; Max Planck Institute of Biophysics, Frankfurt, Germany
Legionella pneumophila causes a severe pneumonia known as Legionnaires’ disease. During the infection, Legionella injects more than 300 effector proteins into host cells. Among them are enzymes involved in altering the host-ubiquitination system. Here, we identified two LegionellaOTU (ovarian tumor)-like deubiquitinases (LOT-DUBs; LotB [Lpg1621/Ceg23] and LotC [Lpg2529]). The crystal structure of the LotC catalytic core (LotC14-310) was determined at 2.4 Å. Unlike the classical OTU-family, the LOT-family shows an extended helical lobe between the Cys-loop and the variable loop, which defines them as a unique class of OTU-DUBs. LotB has an additional ubiquitin-binding site (S1’), which enables the specific cleavage of Lys63-linked polyubiquitin chains. By contrast, LotC only contains the S1 site and cleaves different species of ubiquitin chains. MS analysis of LotB and LotC identified different categories of host-interacting proteins and substrates. Together, our results provide new structural insights into bacterial OTU-DUBs and indicate distinct roles in host–pathogen interactions.