5H35

Crystal structures of the TRIC trimeric intracellular cation channel orthologue from Sulfolobus solfataricus

Summary for 5H35

• Entry DOI: 10.2210/pdb5h35/pdb
• Related: 5H36
• Descriptor: Fab Heavy Chain, Fab Light Chain, Membrane protein TRIC, ... (7 entities in total)
• Functional Keywords: ion channels, immune system-membrane protein complex, immune system/membrane protein
• Biological source: Mus musculus; More
• Total number of polymer chains: 9
• Total formula weight: 220325.41

Authors

Kasuya, G.,Hiraizumi, M.,Hattori, M.,Nureki, O. (deposition date: 2016-10-20, release date: 2017-01-11, Last modification date: 2024-11-13)

Primary citation

Kasuya, G.,Hiraizumi, M.,Maturana, A.D.,Kumazaki, K.,Fujiwara, Y.,Liu, K.,Nakada-Nakura, Y.,Iwata, S.,Tsukada, K.,Komori, T.,Uemura, S.,Goto, Y.,Nakane, T.,Takemoto, M.,Kato, H.E.,Yamashita, K.,Wada, M.,Ito, K.,Ishitani, R.,Hattori, M.,Nureki, O.
Crystal structures of the TRIC trimeric intracellular cation channel orthologues
Cell Res., 26:1288-1301, 2016

PubMed Abstract: Ca release from the sarcoplasmic reticulum (SR) and endoplasmic reticulum (ER) is crucial for muscle contraction, cell growth, apoptosis, learning and memory. The trimeric intracellular cation (TRIC) channels were recently identified as cation channels balancing the SR and ER membrane potentials, and are implicated in Ca signaling and homeostasis. Here we present the crystal structures of prokaryotic TRIC channels in the closed state and structure-based functional analyses of prokaryotic and eukaryotic TRIC channels. Each trimer subunit consists of seven transmembrane (TM) helices with two inverted repeated regions. The electrophysiological, biochemical and biophysical analyses revealed that TRIC channels possess an ion-conducting pore within each subunit, and that the trimer formation contributes to the stability of the protein. The symmetrically related TM2 and TM5 helices are kinked at the conserved glycine clusters, and these kinks are important for the channel activity. Furthermore, the kinks of the TM2 and TM5 helices generate lateral fenestrations at each subunit interface. Unexpectedly, these lateral fenestrations are occupied with lipid molecules. This study provides the structural and functional framework for the molecular mechanism of this ion channel superfamily.

PubMed: 27909292
DOI: 10.1038/cr.2016.140

Experimental method

X-RAY DIFFRACTION (2.642 Å)