7PGI

NaVAb1p (bicelles)

Summary for 7PGI

• Entry DOI: 10.2210/pdb7pgi/pdb
• Related: 7PG8 7PGF 7PGG 7PGP
• Descriptor: Ion transport protein, ACETATE ION, SODIUM ION, ... (4 entities in total)
• Functional Keywords: ion channel membrane protein transport protein antibody complex, membrane protein
• Biological source: Alcanivorax borkumensis (strain ATCC 700651 / DSM 11573 / NCIMB 13689 / SK2)
• Total number of polymer chains: 8
• Total formula weight: 136044.97

Authors

Lolicato, M.,Arrigoni, C. (deposition date: 2021-08-14, release date: 2022-06-08, Last modification date: 2024-01-31)

Primary citation

Arrigoni, C.,Lolicato, M.,Shaya, D.,Rohaim, A.,Findeisen, F.,Fong, L.K.,Colleran, C.M.,Dominik, P.,Kim, S.S.,Schuermann, J.P.,DeGrado, W.F.,Grabe, M.,Kossiakoff, A.A.,Minor Jr., D.L.
Quaternary structure independent folding of voltage-gated ion channel pore domain subunits.
Nat.Struct.Mol.Biol., 29:537-548, 2022

PubMed Abstract: Every voltage-gated ion channel (VGIC) has a pore domain (PD) made from four subunits, each comprising an antiparallel transmembrane helix pair bridged by a loop. The extent to which PD subunit structure requires quaternary interactions is unclear. Here, we present crystal structures of a set of bacterial voltage-gated sodium channel (BacNa) 'pore only' proteins that reveal a surprising collection of non-canonical quaternary arrangements in which the PD tertiary structure is maintained. This context-independent structural robustness, supported by molecular dynamics simulations, indicates that VGIC-PD tertiary structure is independent of quaternary interactions. This fold occurs throughout the VGIC superfamily and in diverse transmembrane and soluble proteins. Strikingly, characterization of PD subunit-binding Fabs indicates that non-canonical quaternary PD conformations can occur in full-length VGICs. Together, our data demonstrate that the VGIC-PD is an autonomously folded unit. This property has implications for VGIC biogenesis, understanding functional states, de novo channel design, and VGIC structural origins.

PubMed: 35655098
DOI: 10.1038/s41594-022-00775-x

Experimental method

X-RAY DIFFRACTION (3.638 Å)