MicroED structure of the human adenosine receptor determined from a single nanocrystal in LCP.
Proc Natl Acad Sci U S A
; 118(36)2021 09 07.
Article
em En
| MEDLINE
| ID: mdl-34462357
ABSTRACT
G protein-coupled receptors (GPCRs), or seven-transmembrane receptors, are a superfamily of membrane proteins that are critically important to physiological processes in the human body. Determining high-resolution structures of GPCRs without bound cognate signaling partners, such as a G protein, requires crystallization in lipidic cubic phase (LCP). GPCR crystals grown in LCP are often too small for traditional X-ray crystallography. These microcrystals are ideal for investigation by microcrystal electron diffraction (MicroED), but the gel-like nature of LCP makes traditional approaches to MicroED sample preparation insurmountable. Here, we show that the structure of a human A2A adenosine receptor can be determined by MicroED after converting the LCP into the sponge phase followed by focused ion-beam milling. We determined the structure of the A2A adenosine receptor to 2.8-Å resolution and resolved an antagonist in its orthosteric ligand-binding site, as well as four cholesterol molecules bound around the receptor. This study lays the groundwork for future structural studies of lipid-embedded membrane proteins by MicroED using single microcrystals that would be impossible with other crystallographic methods.
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Texto completo:
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Bases de dados:
MEDLINE
Assunto principal:
Receptores Purinérgicos P1
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Microscopia Crioeletrônica
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Receptores Acoplados a Proteínas G
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Nanopartículas
Limite:
Humans
Idioma:
En
Revista:
Proc Natl Acad Sci U S A
Ano de publicação:
2021
Tipo de documento:
Article