|Title||The structures and gating mechanism of human calcium homeostasis modulator 2.|
|Journal, issue, pages||Nature, Vol. 576, Issue 7785, Page 163-167, Year 2019|
|Publish date||Nov 27, 2019|
|Authors||Wooyoung Choi / Nicolina Clemente / Weinan Sun / Juan Du / Wei Lü /|
|PubMed Abstract||Calcium homeostasis modulators (CALHMs) are voltage-gated, Ca-inhibited nonselective ion channels that act as major ATP release channels, and have important roles in gustatory signalling and neuronal ...Calcium homeostasis modulators (CALHMs) are voltage-gated, Ca-inhibited nonselective ion channels that act as major ATP release channels, and have important roles in gustatory signalling and neuronal toxicity. Dysfunction of CALHMs has previously been linked to neurological disorders. Here we present cryo-electron microscopy structures of the human CALHM2 channel in the Ca-free active or open state and in the ruthenium red (RUR)-bound inhibited state, at resolutions up to 2.7 Å. Our work shows that purified CALHM2 channels form both gap junctions and undecameric hemichannels. The protomer shows a mirrored arrangement of the transmembrane domains (helices S1-S4) relative to other channels with a similar topology, such as connexins, innexins and volume-regulated anion channels. Upon binding to RUR, we observed a contracted pore with notable conformational changes of the pore-lining helix S1, which swings nearly 60° towards the pore axis from a vertical to a lifted position. We propose a two-section gating mechanism in which the S1 helix coarsely adjusts, and the N-terminal helix fine-tunes, the pore size. We identified a RUR-binding site near helix S1 that may stabilize this helix in the lifted conformation, giving rise to channel inhibition. Our work elaborates on the principles of CALHM2 channel architecture and symmetry, and the mechanism that underlies channel inhibition.|
|External links||PubMed:31776515 / Publisher's page|
|Keywords||TRANSPORT PROTEIN / calcium homeostasis modulator / CALHM2 / TRANSPORT PROTEIN/INHIBITOR / ruthenium red / TRANSPORT PROTEIN-INHIBITOR complex / gap junction|
|Methods||EM (single particle)|
|Resolution||2.7 - 3.5 A|
+About EMN Papers
-Jul 5, 2019. Downlodablable text data
Downlodablable text data
- Some data of EM Navigator services can be downloaded as text file. Software such as Excel can load the data files.
Page Data Format EMN Search search result CSV, TSV, or JSON EMN statistics data table CSV or TSV
Related info.: EMN Search / EMN Statistics
-Jan 31, 2019. EMDB accession codes are about to change! (news from PDBe EMDB page)
EMDB accession codes are about to change! (news from PDBe EMDB page)
- The allocation of 4 digits for EMDB accession codes will soon come to an end. Whilst these codes will remain in use, new EMDB accession codes will include an additional digit and will expand incrementally as the available range of codes is exhausted. The current 4-digit format prefixed with “EMD-” (i.e. EMD-XXXX) will advance to a 5-digit format (i.e. EMD-XXXXX), and so on. It is currently estimated that the 4-digit codes will be depleted around Spring 2019, at which point the 5-digit format will come into force. (see PDBe EMDB page)
- The EM Navigator/Yorodumi systems omit the EMD- prefix.
Related info.: Q: What is "EMD"? / ID/Accession-code notation in Yorodumi/EM Navigator
+Feb 20, 2018. PDBj/BINDS workshop in Osaka University
PDBj/BINDS workshop in Osaka University
+Oct 4, 2017. Three pioneers of this field were awarded Nobel Prize in Chemistry 2017
Three pioneers of this field were awarded Nobel Prize in Chemistry 2017
- Jacques Dubochet (University of Lausanne, Switzerland) is a pioneer of ice-embedding method of EM specimen (as known as cryo-EM), Most of 3DEM structures in EMDB and PDB are obtained using his method.
- Joachim Frank (Columbia University, New York, USA) is a pioneer of single particle reconstruction, which is the most used reconstruction method for 3DEM structures in EMDB and EM entries in PDB. And also, he is a develper of Spider, which is one of the most famous software in this field, and is used for some EM Navigor data (e.g. map projection/slice images).
- Richard Henderson (MRC Laboratory of Molecular Biology, Cambridge, UK) was determined the first biomolecule structure by EM. The first EM entry in PDB, PDB-1brd is determinedby him.
External links: The 2017 Nobel Prize in Chemistry - Press Release
+Jul 12, 2017. Major update of PDB
Major update of PDB
- wwPDB released updated PDB data conforming to the new PDBx/mmCIF dictionary. This is a major update changing the version number from 4 to 5, and with Remediation, in which all the entries are updated. See below links for details.
- In this update, many items about electron microscopy experimental information are reorganized (e.g. em_software). Now, EM Navigator and Yorodumi are based on the updated data.
Database of articles cited by 3DEM data entries
- Database of articles cited by 3DEM data entries in EMDB and PDB
- Using PubMed data
Related info.: EMDB / PDB / Q: What is the data source of EM Navigator? / EM Navigator / Yorodumi Papers / Changes in new EM Navigator and Yorodumi