3beh

Publication Abstract from PubMed

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.

Structure of the transmembrane regions of a bacterial cyclic nucleotide-regulated channel.,Clayton GM, Altieri S, Heginbotham L, Unger VM, Morais-Cabral JH Proc Natl Acad Sci U S A. 2008 Feb 5;105(5):1511-5. Epub 2008 Jan 23. PMID:18216238^[1]

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.