8TMQ
Cryo-EM structure of magnesium depleted CorA in complex with conformation-specific synthetic antibody C18, State MGD-1A
Summary for 8TMQ
| Entry DOI | 10.2210/pdb8tmq/pdb |
| Related | 8TMB 8TMC 8TMD 8TME 8TMF 8TMG 8TMH 8TMI 8TMJ 8TMK 8TML 8TMM 8TMN 8TMO 8TMP |
| EMDB information | 41398 |
| Descriptor | sAB C18 Light Chain, sAB C18 Heavy Chain, Cobalt/magnesium transport protein CorA, ... (4 entities in total) |
| Functional Keywords | ion channel, magnesium channel, membrane protein |
| Biological source | Homo sapiens More |
| Total number of polymer chains | 7 |
| Total formula weight | 268850.12 |
| Authors | Erramilli, S.K.,Perozo, E.,Kossiakoff, A.A. (deposition date: 2023-07-29, release date: 2025-02-12, Last modification date: 2026-02-25) |
| Primary citation | Erramilli, S.K.,Nosol, K.,Pietrzak-Lichwa, K.,Schmandt, N.,Li, T.,Tokarz, P.,Hou, J.,Zhao, M.,Perozo, E.,Kossiakoff, A.A. Conformational ensembles of the magnesium channel CorA reveal structural basis for channel gating. Proc.Natl.Acad.Sci.USA, 123:e2512532123-e2512532123, 2026 Cited by PubMed Abstract: In prokaryotes, CorA is the primary influx pathway for magnesium, a critical divalent cation in cellular physiology and biochemistry. Mechanistic studies show that homopentameric CorA is regulated through an intracellular [Mg]-dependent negative feedback loop, involving the asymmetric participation of individual subunits. To understand the connection between asymmetry and activation, we used single-particle cryo-EM to solve sixteen structures of nanodisc-reconstituted CorA. We utilized conformation-specific synthetic antibodies to stabilize subtle but significant conformational differences in the cryo-EM structures. Our results demonstrate that CorA exists as a set of conformational ensembles, where population size inversely correlates with intracellular Mg concentration. These ensembles include channels with a variety of pore conformations, both constricted and dilated, suggesting a spectrum of active CorA functional states. The ensembles connect asymmetric structural transitions in the cytoplasmic domain with conformational changes in the permeation pathway via an electrostatic network, ultimately controlling channel-gating events. We believe that these results establish a framework for understanding magnesium homeostasis in prokaryotic systems. PubMed: 41701836DOI: 10.1073/pnas.2512532123 PDB entries with the same primary citation |
| Experimental method | ELECTRON MICROSCOPY (3.1 Å) |
Structure validation
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