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-Structure paper
Title | Flexible architecture of IP3R1 by Cryo-EM. |
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Journal, issue, pages | Structure, Vol. 19, Issue 8, Page 1192-1199, Year 2011 |
Publish date | Aug 10, 2011 |
![]() | Steven J Ludtke / Thao P Tran / Que T Ngo / Vera Yu Moiseenkova-Bell / Wah Chiu / Irina I Serysheva / ![]() |
PubMed Abstract | Inositol 1,4,5-trisphosphate receptors (IP3Rs) play a fundamental role in generating Ca2+ signals that trigger many cellular processes in virtually all eukaryotic cells. Thus far, the three- ...Inositol 1,4,5-trisphosphate receptors (IP3Rs) play a fundamental role in generating Ca2+ signals that trigger many cellular processes in virtually all eukaryotic cells. Thus far, the three-dimensional (3D) structure of these channels has remained extremely controversial. Here, we report a subnanometer resolution electron cryomicroscopy (cryo-EM) structure of a fully functional type 1 IP3R from cerebellum in the closed state. The transmembrane region reveals a twisted bundle of four α helices, one from each subunit, that form a funnel shaped structure around the 4-fold symmetry axis, strikingly similar to the ion-conduction pore of K+ channels. The lumenal face of IP3R1 has prominent densities that surround the pore entrance and similar to the highly structured turrets of Kir channels. 3D statistical analysis of the cryo-EM density map identifies high variance in the cytoplasmic region. This structural variation could be attributed to genuine structural flexibility of IP3R1. |
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Methods | EM (single particle) |
Resolution | 9.5 Å |
Structure data | ![]() EMDB-5278: |
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