6O7C

Crystal structure of the LjCASTOR gating ring in the Ca2+ and K+ state

Summary for 6O7C

• Entry DOI: 10.2210/pdb6o7c/pdb
• Descriptor: Ion channel CASTOR, CALCIUM ION, MAGNESIUM ION, ... (6 entities in total)
• Functional Keywords: calcium channel, rck domain, gating ring, castor, membrane protein, transport protein
• Biological source: Lotus japonicus
• Total number of polymer chains: 1
• Total formula weight: 60743.91

Authors

Jiang, Y.,Kim, S. (deposition date: 2019-03-07, release date: 2019-09-11, Last modification date: 2024-03-13)

Primary citation

Kim, S.,Zeng, W.,Bernard, S.,Liao, J.,Venkateshwaran, M.,Ane, J.M.,Jiang, Y.
Ca2+-regulated Ca2+channels with an RCK gating ring control plant symbiotic associations.
Nat Commun, 10:3703-3703, 2019

PubMed Abstract: A family of plant nuclear ion channels, including DMI1 (Does not Make Infections 1) and its homologs CASTOR and POLLUX, are required for the establishment of legume-microbe symbioses by generating nuclear and perinuclear Ca spiking. Here we show that CASTOR from Lotus japonicus is a highly selective Ca channel whose activation requires cytosolic/nucleosolic Ca, contrary to the previous suggestion of it being a K channel. Structurally, the cytosolic/nucleosolic ligand-binding soluble region of CASTOR contains two tandem RCK (Regulator of Conductance for K) domains, and four subunits assemble into the gating ring architecture, similar to that of large conductance, Ca-gated K (BK) channels despite the lack of sequence similarity. Multiple ion binding sites are clustered at two locations within each subunit, and three of them are identified to be Ca sites. Our in vitro and in vivo assays also demonstrate the importance of these gating-ring Ca binding sites to the physiological function of CASTOR as well as DMI1.

PubMed: 31420535
DOI: 10.1038/s41467-019-11698-5

Experimental method

X-RAY DIFFRACTION (1.85 Å)