Cryo-EM structure of the calcium release-activated calcium channel Orai in an open conformation Journal Article

   

Authors:	Hou, X.; Outhwaite, I. R.; Pedi, L.; Long, S. B.
Article Title:	Cryo-EM structure of the calcium release-activated calcium channel Orai in an open conformation
Abstract:	The calcium release-activated calcium channel Orai regulates Ca2+ entry into non-excitable cells and is required for proper immune function. While the channel typically opens following Ca2+ release from the endoplasmic reticulum, certain pathologic mutations render the channel constitutively open. Previously, using one such mutation (H206A), we obtained low (6.7 Å) resolution X-ray structural information on Drosophila melanogaster Orai in an open conformation (Hou et al., 2018). Here we present a structure of this open conformation at 3.3 Å resolution using fiducial-assisted cryo-electron microscopy. The improved structure reveals the conformations of amino acids in the open pore, which dilates by outward movements of subunits. A ring of phenylalanine residues repositions to expose previously shielded glycine residues to the pore without significant rotational movement of the associated helices. Together with other hydrophobic amino acids, the phenylalanines act as the channel’s gate. Structured M1–M2 turrets, not evident previously, form the channel’s extracellular entrance. © Hou et al.
Journal Title:	eLife
Volume:	9
ISSN:	2050-084X
Publisher:	eLife Sciences Publications Ltd.
Date Published:	2020-11-30
Start Page:	e62772
Language:	English
DOI:	10.7554/eLife.62772
PUBMED:	33252040
PROVIDER:	scopus
PMCID:	PMC7723414
DOI/URL:	https://www.scopus.com/inward/record.uri?eid=2-s2.0-85097541727&doi=10.7554%2feLife.62772&partnerID=40&md5=f66c53fe4a9fa0a7d90644c0d91354e3
Notes:	Article -- Export Date: 4 January 2021 -- Source: Scopus

https://synapse.mskcc.org/synapse/works/has_related_data_chk/174789