Structural insights into Legionella RidL-Vps29 retromer subunit interaction reveal displacement of the regulator TBC1D5.
Barlocher, K., Hutter, C.A.J., Swart, A.L., Steiner, B., Welin, A., Hohl, M., Letourneur, F., Seeger, M.A., Hilbi, H.(2017) Nat Commun 8: 1543-1543
- PubMed: 29146912 
- DOI: https://doi.org/10.1038/s41467-017-01512-5
- Primary Citation of Related Structures:  
5OH5, 5OH6 - PubMed Abstract: 
Legionella pneumophila can cause Legionnaires' disease and replicates intracellularly in a distinct Legionella-containing vacuole (LCV). LCV formation is a complex process that involves a plethora of type IV-secreted effector proteins. The effector RidL binds the Vps29 retromer subunit, blocks retrograde vesicle trafficking, and promotes intracellular bacterial replication. Here, we reveal that the 29-kDa N-terminal domain of RidL (RidL 2-281 ) adopts a "foot-like" fold comprising a protruding β-hairpin at its "heel". The deletion of the β-hairpin, the exchange to Glu of Ile 170 in the β-hairpin, or Leu 152 in Vps29 abolishes the interaction in eukaryotic cells and in vitro. RidL 2-281 or RidL displace the Rab7 GTPase-activating protein (GAP) TBC1D5 from the retromer and LCVs, respectively, and TBC1D5 promotes the intracellular growth of L. pneumophila. Thus, the hydrophobic β-hairpin of RidL is critical for binding of the L. pneumophila effector to the Vps29 retromer subunit and displacement of the regulator TBC1D5.
Organizational Affiliation: 
Institute of Medical Microbiology, University of Zürich, Gloriastrasse 30, 8006, Zürich, Switzerland.