In:
Nature, Springer Science and Business Media LLC, Vol. 594, No. 7864 ( 2021-06-24), p. 594-598
Abstract:
G-protein-coupled receptors (GPCRs) have central roles in intercellular communication 1,2 . Structural studies have revealed how GPCRs can activate G proteins. However, whether this mechanism is conserved among all classes of GPCR remains unknown. Here we report the structure of the class-C heterodimeric GABA B receptor, which is activated by the inhibitory transmitter GABA, in its active form complexed with G i1 protein. We found that a single G protein interacts with the GB2 subunit of the GABA B receptor at a site that mainly involves intracellular loop 2 on the side of the transmembrane domain. This is in contrast to the G protein binding in a central cavity, as has been observed with other classes of GPCR. This binding mode results from the active form of the transmembrane domain of this GABA B receptor being different from that of other GPCRs, as it shows no outside movement of transmembrane helix 6. Our work also provides details of the inter- and intra-subunit changes that link agonist binding to G-protein activation in this heterodimeric complex.
Type of Medium:
Online Resource
ISSN:
0028-0836
,
1476-4687
DOI:
10.1038/s41586-021-03507-1
Language:
English
Publisher:
Springer Science and Business Media LLC
Publication Date:
2021
detail.hit.zdb_id:
120714-3
detail.hit.zdb_id:
1413423-8
SSG:
11