3BEH

Structure of a Bacterial Cyclic Nucleotide Regulated Ion Channel

Summary for 3BEH

• Entry DOI: 10.2210/pdb3beh/pdb
• Descriptor: Mll3241 protein, POTASSIUM ION, LAURYL DIMETHYLAMINE-N-OXIDE, ... (4 entities in total)
• Functional Keywords: transmembrane protein, membrane protein
• Biological source: Mesorhizobium loti
• Cellular location: Cell membrane; Multi-pass membrane protein: Q98GN8
• Total number of polymer chains: 4
• Total formula weight: 152178.29

Authors

Clayton, G.M.,Morais-Cabral, J.H. (deposition date: 2007-11-18, release date: 2008-01-15, Last modification date: 2024-02-21)

Primary citation

Clayton, G.M.,Altieri, S.,Heginbotham, L.,Unger, V.M.,Morais-Cabral, J.H.
Structure of the transmembrane regions of a bacterial cyclic nucleotide-regulated channel.
Proc.Natl.Acad.Sci.USA, 105:1511-1515, 2008

PubMed Abstract: The six-transmembrane helix (6 TM) tetrameric cation channels form the largest ion channel family, some members of which are voltage-gated and others are not. There are no reported channel structures to match the wealth of functional data on the non-voltage-gated members. We determined the structure of the transmembrane regions of the bacterial cyclic nucleotide-regulated channel MlotiK1, a non-voltage-gated 6 TM channel. The structure showed how the S1-S4 domain and its associated linker can serve as a clamp to constrain the gate of the pore and possibly function in concert with ligand-binding domains to regulate the opening of the pore. The structure also led us to hypothesize a new mechanism by which motions of the S6 inner helices can gate the ion conduction pathway at a position along the pore closer to the selectivity filter than the canonical helix bundle crossing.

PubMed: 18216238
DOI: 10.1073/pnas.0711533105

Experimental method

X-RAY DIFFRACTION (3.1 Å)