Molecular mechanisms of cyclic nucleotide-gated channels.
Cyclic nucleotide-gated (CNG) channels are highly specialized to carry out their unique role in cell signalling. Significant progress has been made in the last several years determining the molecular mechanisms for these specializations. The activation of the channels begins with the binding of cyclic nucleotide to a domain in the carboxyl terminal region. This binding, in turn, produces an induced fit of the protein that involves a movement of the C-helix portion of the binding domain. The induced fit of the binding domain is coupled to an allosteric conformational change that opens the channel pore. The pore is formed primarily from the sequence between the S5 and S6 segments. A single glutamic acid in the pore represents the binding site for multiple monovalent cations, the blocking site for external divalent cations, and the site for the effect of protons on permeation.
Zagotta
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Department of Physiology and Biophysics, Howard Hughes Medical Institute, University of Washington, School of Medicine, Seattle 98195-7290, USA.
D000595:Amino Acid Sequence; D003001:Cloning, Molecular; D007473:Ion Channels / Q000235:genetics / Q000502:physiology*; D008958:Models, Molecular; D008969:Molecular Sequence Data; D009712:Nucleotides, Cyclic / Q000502:physiology*; D011487:Protein Conformation; D013329:Structure-Activity Relationship
D007473:Ion Channels; D009712:Nucleotides, Cyclic