LDL receptor
FunctionLDL (Low Density Lipoprotein) receptor (LDLR) mediates the endocytosis of cholesterol-rich LDL. LDLR recognizes the apoprotein B100 which is embedded in the outer layer of the LDL particle. LDLR sits on the cell surface and binds LDL particles which circulate in the blood stream. LDLR transports the LDL particle into the cell where the cholesterol is used. Upon release of the LDL particle, the LDLR is recycled back into the cell membrane surface[1]. See also Transmembrane (cell surface) receptors DiseaseMutations in LDLR which cause its lack of function are causing familial hypercholesterolemia[2]. Structural highlightsLDLR complex with proprotein convertase subtilisin/kexin 9-CoA reductase and Ca+2 ions. Ligand-binding domain (LBD) and epidermal growth factor precursor homology domain (EGFP) of LDLR. LDLR consists of a ligand-binding domain (LBD residues 1-292), epidermal growth factor precursor homology domain (EGFP residues 293-699), oligosaccharide-rich domain (residues 700-758), membrane-spanning domain (residues 759-781) and cytoplasmic domain (residues 782-832). LDLR LBD contains 7 ca. 40 amino acid long repeats (LB1 residues 20-67; LB2 residues 55-104; LB3 residues 105-143; LB4 residues 144-196; LB5 residues 196-232; LB6 residues 234-272) containing 6 cysteine residues, making a calcium binding octahedral structure. LDLR EGFP contains 2 EGF repeats followed by 6 YWTD repeats and another EGF repeat. LDLR LBD residues 133-273 are named C-type lectin-like domain.
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3D structures of LDL receptor
Updated on 26-October-2025
- hLDLR ligand-binding domain;Repeats - LB1 20-67; LB2 55-104; LB4 144-195; LB5 196-232; LB6 234-272; LB7 274-313
- Transmembrane (cell surface) receptors – hLDLR LB1 - human - NMR
- 1ldr – hLDLR LB2 - NMR
- 1ajj – hLDLR LB5
- 1d2j, 1f8z – hLDLR LB6 - NMR
- 1f5y – hLDLR LB1,LB2 - NMR
- 2lgp – hLDLR LB4,LB5 - NMR
- 1xfe – hLDLR LB7,EGF - NMR
- 1yxj, 1yxk, 6tl7, 6tla – hLDLR LBD LB4,LB5,LB6
- 6tl9 – hLDLR LBD LB4,LB5,LB6 + inhibitor
- Transmembrane (cell surface) receptors – hLDLR LB1 - human - NMR
- hLDLR ligand-binding domain complex with protein
- hLDLR EGFP domain 263-699
- hLDLR EGFP complex with protein
- hLDLR cytoplasmic domain C terminal 817-832
- 3so6 – hLDLR C terminal + LDLR adaptor protein
- 3so6 – hLDLR C terminal + LDLR adaptor protein
- hLDLR lectin-like domain 136-273
- hLDLR Cys-rich domain 70-190
- 6byv – hLDLR - NMR
- 6byv – hLDLR - NMR
- hLDLR multiple domains
- 1n7d – hLDLR LBD,EGFP domains
- 3m0c – hLDLR LBD,EGFP, oligosaccharide-rich, membrane-spanning domains + proprotein convertase subtilisin/kexin 9
- 3p5b, 3p5c – hLDLR EGFP, oligosaccharide-rich, domains + proprotein convertase subtilisin/kexin 9
- 9bdt, 9coo – hLDLR + apolipoprotein B + legobody + nanobody + MBP – Cryo EM
- 9bd8, 9bde – hLDLR + apolipoprotein B – Cryo EM
- 1n7d – hLDLR LBD,EGFP domains