Biological membranes are unlike simple boundaries, but functional media of complex compositions where proteins workout their roles as receptors, transducers and transporters. Membranes constantly exchange their lipid components via specific lipid transport proteins to ensure this functional complexity is maintained. But, who is conducting this orchestra of exchanging, loading and tethering ?
This seminar will focus on how computer simulations, in both coarse-grained and all-atom resolutions, can help to develop hypotheses on the structural/functional connection underneath this constant protein-lipid interplay. We will present two molecular machines : The human multidrug efflux pump and ABC transporter Pgp, and the lipid transporter RV1410 together with its functional partner LprG from mycobacteria. We will explore : i) How a highly specialized lipid environment modulates Pgp flexibility and might play a role in substrate accessibility. ii) How RV1410 and LprG team up to extract triacylglycerides from the bilayer into the periplasm and contribute to seal the outer mycomembrane.