TY - JOUR T1 - The immunodominant protein P116 extracts cholesterol and other essential lipids JF - bioRxiv DO - 10.1101/2022.06.28.498018 SP - 2022.06.28.498018 AU - Lasse Sprankel AU - David Vizarraga AU - Jesús Martín AU - Sina Manger AU - Jakob Meier-Credo AU - Marina Marcos AU - Josep Julve AU - Noemi Rotllan AU - Margot P. Scheffer AU - Joan Carles Escolà-Gil AU - Julian D. Langer AU - Jaume Piñol AU - Ignacio Fita AU - Achilleas S. Frangakis Y1 - 2022/01/01 UR - http://biorxiv.org/content/early/2022/07/01/2022.06.28.498018.abstract N2 - Many human pathogens need to extract lipids from their environment for survival and proliferation. How this is accomplished on a molecular level is largely unknown1. Here, we report a comprehensive structural and functional analysis of the previously uncharacterized protein P116 (MPN_213) from Mycoplasma pneumoniae, a human pathogen responsible for approximately 30% of community-acquired human pneumonia2. Single-particle cryo-electron microscopy of P116 at 3.3 Å resolution reveals a homodimer with a core domain presenting a previously unseen fold. This fold creates a large cavity of ∼18,000 Å3 with a hydrophobic internal surface that is accessible to solvent. Within the cavity ligands with a length of 10-19 Å and a width of 4 Å could be observed. These ligands were identified as the essential lipids phosphatidylcholine, sphingomyelin and cholesterol using mass spectrometry. When the cavity is emptied, the protein undergoes an extensive conformational change that can no longer accommodate lipids. When emptied P116 is incubated with high-density lipoproteins (HDLs) a net transfer of cholesterol is demonstrated by a radioactivity experiment and cryo-electron microscopy resolves a complex between P116 and HDL. Taken together, our results reveal the mechanism by which P116 extracts essential lipids from the host environment and possibly then delivers them into the membrane by a wringing movement. This mechanism may be precedential for other cholesterol-auxotrophic bacteria.Competing Interest StatementThe authors have declared no competing interest. ER -