| Definition |
A cyclic nucleotide-regulated channel protein that is the modulatory subunit of the cyclic nucleotide-gated channel (CNG channel). It consists of amino- and carboxyl-terminal intracellular domains separated by a domain (common with other ion channels) containing six transmembrane helices (S1-S6) in which the last two helices (S5 and S6) flank a loop, called the pore loop, which determines ion selectivity. The carboxy-terminal region contains the Cyclic nucleotide-binding domain (Pfam:PF00027) (CNBD) and a region connecting the CNBD to the S6 segment (C-linker), which is important for modulation by transition metals. CNG beta subunits combine with the alpha subunits to form the cyclic nucleotide-gated ion channels, which mediate sensory transduction in photoreceptors and olfactory sensory neurons. These channels are likely composed of four subunits around a centrally located ion-permeable pore that opens in response to the direct binding of intracellular cyclic nucleotides. CNG channels are non-selective cation channels. They are not gated by membrane voltage although their structure includes the transmembrane S4 motif known to function as the membrane voltage sensor in all voltage-gated ion channels, but it has been shown to be important for proper folding and processing. Alpha and beta subunits of the CNG channel are very similar, however the beta subunits are not able to form functional channels by themselves.
[PRO:CNA]
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DAG
OLS
Cytoscape
