Scientists decipher how the bacteria that causes 30% of community-acquired pneumonia is able to survive
A team led by the Institute of Molecular Biology of Barcelona (IBMB-CSIC), based in the Barcelona Science Park, and the Buchmann Institute for Molecular Life Sciences (BMLS) in Germany has deciphered the structure and functioning of the P116 protein, through which the bacterium Mycoplasma pneumoniae obtains cholesterol and other lipids which are necessary for its survival. The results of the study, published in the Nature Structural & Molecular Biology journal, open up new therapeutic possibilities to block the infectious capacity of this pathogen, and also suggest several applications in biotechnology.
The Mycoplasma pneumoniae bacterium is responsible for about 30% of atypical pneumonias and other respiratory infections at all ages, but especially in children. This type of bacterium needs lipids, such as cholesterol, which it must pick up from its host in order to survive.
Now, a new study led by researchers Ignacio Fita and Achilleas Frangakis from the Institute of Molecular Biology of Barcelona of the CSIC (IBMB-CSIC) and the Buchmann Institute for Molecular Life Sciences (BMLS) of Germany, respectively, has identified and studied the structure and functioning of the P116 protein, through which, the bacterium M. pneumoniae traps cholesterol and other lipids it needs to maintain the integrity of its membrane and survive.
The team has used advanced electron microscopy technology at cryogenic temperatures to study the P116 protein, which has revealed an original structure. As Ignacio Fita explains, “the structure contains a large completely hydrophobic cavity capable of housing different lipid compounds.”
The mass spectrometry technology and the use of radioisotopes enabled a highly accurate analysis to be carried out on the different essential lipids that could be stored in the P116 cavity. The research team’s analysis shows that P116 can extract specific lipids such as phosphatidylcholine, sphingomyelin and cholesterol from the medium, and that it can even get cholesterol from lipoproteins in the host’s bloodstream.
“These results can open up new therapeutic possibilities to block the function of the P116 protein and, therefore, the infectious ability of Mycoplasma pneumoniae. Different applications in biotechnology also arise,” adds David Vizarraga, researcher at IBMB-CSIC, one of the first signatories of the work together with Lasse Sprankel, from the Buchmann Institute (Germany).
Researchers Jesus Martín from IBMB-CSIC; Marina Marcos and Jaume Piñol from the Autonomous University of Barcelona (UAB) also participated in the study, along with; Josep Julve, Noemi Rotllan and Joan Carles Escolà-Gil, from the Research Institute of the Santa Creu i Sant Pau Hospital and CIBERDEM, as well as researchers from the Max Planck Institute of Biophysics in Germany.
» Reference article: Vizarraga & L. Sprankel J. Martín, S. Manger, J. Meier-Credo, M. Marcos, J. Julve, N. Rotllan, M P. Scheffer, JC. Escolà-Gil, J. D. Langer, J. Piñol, I. Fita & A. Frangakis. “Essential protein P116 extracts cholesterol and other indispensable lipids for Mycoplasmas”. Nature Structural & Molecular biology (2023). Doi: https://doi.org/10.1038/s41594-023-00922-y