6W25 image
Entry Detail
PDB ID:
6W25
Title:
Crystal structure of the Melanocortin-4 Receptor (MC4R) in complex with SHU9119
Biological Source:
PDB Version:
Deposition Date:
2020-03-04
Release Date:
2020-04-29
Method Details:
Experimental Method:
Resolution:
2.75 Å
R-Value Free:
0.25
R-Value Work:
0.23
R-Value Observed:
0.23
Space Group:
C 1 2 1
Macromolecular Entities
Polymer Type:polypeptide(L)
Description:Melanocortin receptor 4,GlgA glycogen synthase,Melanocortin receptor 4
Chain IDs:A
Chain Length:535
Number of Molecules:1
Biological Source:Homo sapiens, Pyrococcus abyssi
Polymer Type:polypeptide(L)
Description:SHU9119
Chain IDs:B
Chain Length:9
Number of Molecules:1
Biological Source:synthetic construct
Modified Residue
Compound ID Chain ID Parent Comp ID Details 2D Image
YCM A CYS modified residue
Primary Citation
Determination of the melanocortin-4 receptor structure identifies Ca2+as a cofactor for ligand binding.
Science 368 428 433 (2020)
PMID: 32327598 DOI: 10.1126/science.aaz8995

Abstact

The melanocortin-4 receptor (MC4R) is involved in energy homeostasis and is an important drug target for syndromic obesity. We report the structure of the antagonist SHU9119-bound human MC4R at 2.8-angstrom resolution. Ca2+ is identified as a cofactor that is complexed with residues from both the receptor and peptide ligand. Extracellular Ca2+ increases the affinity and potency of the endogenous agonist α-melanocyte-stimulating hormone at the MC4R by 37- and 600-fold, respectively. The ability of the MC4R crystallized construct to couple to ion channel Kir7.1, while lacking cyclic adenosine monophosphate stimulation, highlights a heterotrimeric GTP-binding protein (G protein)-independent mechanism for this signaling modality. MC4R is revealed as a structurally divergent G protein-coupled receptor (GPCR), with more similarity to lipidic GPCRs than to the homologous peptidic GPCRs.

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Primary Citation of related structures