Crystal structure of the Legionella effector Lem22
Guennadi Kozlov1, Kathy Wong1, Kalle Gehring1
1Department of Biochemistry, Groupe de recherche axé sur la structure des protéines, McGill University, Montreal, QC, H3G 0B1, Canada.
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Legionella pneumophila is a pathogen causing severe pneumonia in humans called Legionnaires' disease. Lem22 is a previously uncharacterized effector protein conserved in multiple Legionella strains. Here, we report the crystal structure of Lem22 from the Philadelphia strain, also known as lpg2328, at 1.40 Å resolution. The structure shows an up-and-down three-helical bundle with a significant structural similarity to a number of protein-binding domains involved in apoptosis and membrane trafficking. Sequence conservation identifies a putative functional site on the interface of helices 2 and 3. The structure is an important step toward a functional characterization of Lem22.
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