{"entity": "publication", "iuid": "b4a131b39b9444f19c8c6e8f428c11d1", "timestamp": "2026-08-20T20:36:45.841Z", "links": {"self": {"href": "https://publications-affiliated.scilifelab.se/publication/b4a131b39b9444f19c8c6e8f428c11d1.json"}, "display": {"href": "https://publications-affiliated.scilifelab.se/publication/b4a131b39b9444f19c8c6e8f428c11d1"}}, "title": "Calcium stabilizes the flexible N-terminal domain of the bacterial ion channel DeCLIC.", "authors": [{"family": "Fan", "given": "Chen", "initials": "C"}, {"family": "Lycksell", "given": "Marie", "initials": "M"}, {"family": "Zhuang", "given": "Yuxuan", "initials": "Y"}, {"family": "Howard", "given": "Rebecca J", "initials": "RJ"}, {"family": "Lindahl", "given": "Erik", "initials": "E"}], "type": "journal article", "published": "2025-12-00", "journal": {"title": "J Struct Biol X", "issn": "2590-1524", "volume": "12", "pages": "100139", "issn-l": null}, "abstract": "Pentameric ligand-gated ion channels (pLGICs) are responsible for the rapid conversion of chemical to electrical signals. In addition to the canonical extracellular and transmembrane domains, some prokaryotic pLGICs contain an N-terminal domain (NTD) of unclear structure and function. In one such case, the calcium-sensitive channel DeCLIC, the NTD appears to accelerate gating; however, its evident flexibility has posed a challenge to model building, and its role in calcium sensitivity is unclear. Here we report cryo-EM structures of DeCLIC in circularized lipid nanodiscs, achieving the highest resolution reported so far, and enabling definition of calcium-binding sites in both the N-terminal and canonical extracellular domains. In addition to the symmetric state, calcium depletion promoted an asymmetric conformation of the NTD, offering a structural rationale for small-angle scattering results. Behavior of these structures in molecular dynamics simulations demonstrated calcium stabilization of the NTD. These features of DeCLIC offer a model system for ion-channel modulation by a flexible accessory domain, potentially conserved in structurally homologous systems across evolution.", "doi": "10.1016/j.yjsbx.2025.100139", "pmid": "41328424", "labels": [], "xrefs": [{"db": "pmc", "key": "PMC12664993"}, {"db": "pii", "key": "S2590-1524(25)00020-0"}], "notes": [], "created": "2026-08-20T08:06:58.443Z", "modified": "2026-08-20T08:06:58.487Z"}