Interactions between membrane proteins and lipid membrane revealed by cryoEM

Membrane proteins and membrane lipids are essential partners in various biological processes, and elucidating their structures in a natural membrane environment is crucial for enhancing our understanding of their intricate interactions. However, resolving high-resolution structures of lipids and membrane proteins under physiological conditions presents considerable challenges due to limitations in experimental techniques and instrumentation, leaving these interactions inadequately understood and necessitating further investigation. In this review, we summarize current sample preparation methods and tools for studying lipid-membrane protein interactions using cryo-electron microscopy (cryo-EM), including nanodiscs, styrene-maleic acid copolymers, liposomes, and in situ analyses. We also highlight several up-to-date examples of high-resolution lipid-membrane protein complexes that reveal how lipids influence the functionality of membrane proteins, featuring the innovative methodologies employed. Additionally, we provide a concise overview of the steps involved in cryo-EM analysis of membrane proteins and summarize recent advancements in deep learning techniques for model construction. We discuss how the intersection of artificial intelligence and structural biology offers a fertile ground for breaking through current technological barriers, promising to unravel the complexities of molecular dynamics and providing a holistic view of biomolecular interactions.