Structure of apolipoprotein B100 bound to the low-density lipoprotein receptor.
Reimund, M., Dearborn, A.D., Graziano, G., Lei, H., Ciancone, A.M., Kumar, A., Holewinski, R., Neufeld, E.B., O'Reilly, F.J., Remaley, A.T., Marcotrigiano, J.(2024) Nature
- PubMed: 39663455
- DOI: https://doi.org/10.1038/s41586-024-08223-0
- Primary Citation of Related Structures:
9BD1, 9BD8, 9BDE, 9BDT, 9COO - PubMed Abstract:
Apolipoprotein B100 (apoB100) is a structural component of low-density lipoprotein (LDL) and a ligand for the LDL receptor (LDLR) 1 . Mutations in apoB100 or in LDLR cause familial hypercholesterolaemia, an autosomal dominant disease that is characterized by a marked increase in LDL cholesterol (LDL-C) and a higher risk of cardiovascular disease 2 . The structure of apoB100 on LDL and its interaction with LDLR are poorly understood. Here we present the cryo-electron microscopy structures of apoB100 on LDL bound to the LDLR and a nanobody complex, which can form a C 2 -symmetric, higher-order complex. Using local refinement, we determined high-resolution structures of the interfaces between apoB100 and LDLR. One binding interface is formed between several small-ligand-binding modules of LDLR and a series of basic patches that are scattered along a β-belt formed by apoB100, encircling LDL. The other binding interface is formed between the β-propeller domain of LDLR and the N-terminal domain of apoB100. Our results reveal how both interfaces are involved in LDL dimer formation, and how LDLR cycles between LDL- and self-bound conformations. In addition, known mutations in either apoB100 or LDLR, associated with high levels of LDL-C, are located at the LDL-LDLR interface.
Organizational Affiliation:
Lipoprotein Metabolism Laboratory, Translational Vascular Medicine Branch, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, MD, USA.