Structural highlights
5khk is a 1 chain structure with sequence from Lk3 transgenic mice. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance.
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| Ligands: | |
| NonStd Res: | |
| Related: | 5khg, 5khh, 5khi, 5khj |
| Gene: | Hcn2, Bcng2, Hac1 (LK3 transgenic mice) |
| Resources: | FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT |
Function
[HCN2_MOUSE] Hyperpolarization-activated ion channel exhibiting weak selectivity for potassium over sodium ions. Contributes to the native pacemaker currents in heart (If) and in neurons (Ih). Can also transport ammonium in the distal nephron. Produces a large instantaneous current. Activated by cAMP. Modulated by intracellular chloride ions and pH; acidic pH shifts the activation to more negative voltages.[1]
Publication Abstract from PubMed
Cyclic AMP is thought to facilitate the opening of the HCN2 channel by binding to a C-terminal domain and promoting or inhibiting interactions between subunits. Here, we correlated the ability of cyclic nucleotides to promote interactions of isolated HCN2 C-terminal domains in solution with their ability to facilitate channel opening. Cyclic IMP, a cyclic purine nucleotide, and cCMP, a cyclic pyrimidine nucleotide, bind to a C-terminal domain containing the cyclic nucleotide-binding domain but, in contrast to other cyclic nucleotides examined, fail to promote its oligomerization, and produce only modest facilitation of opening of the full-length channel. Comparisons between ligand bound structures identify a region between the sixth and seventh beta strands and the distal C helix as important for facilitation and tight binding. We propose that promotion of interactions between the C-terminal domains by a given ligand contribute to its ability to facilitate opening of the full-length channel.
Cyclic Purine and Pyrimidine Nucleotides Bind to the HCN2 Ion Channel and Variably Promote C-Terminal Domain Interactions and Opening.,Ng LC, Putrenko I, Baronas V, Van Petegem F, Accili EA Structure. 2016 Aug 23. pii: S0969-2126(16)30193-9. doi:, 10.1016/j.str.2016.06.024. PMID:27568927[2]
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.
See Also
References
- ↑ Proenza C, Angoli D, Agranovich E, Macri V, Accili EA. Pacemaker channels produce an instantaneous current. J Biol Chem. 2002 Feb 15;277(7):5101-9. Epub 2001 Dec 7. PMID:11741901 doi:http://dx.doi.org/10.1074/jbc.M106974200
- ↑ Ng LC, Putrenko I, Baronas V, Van Petegem F, Accili EA. Cyclic Purine and Pyrimidine Nucleotides Bind to the HCN2 Ion Channel and Variably Promote C-Terminal Domain Interactions and Opening. Structure. 2016 Aug 23. pii: S0969-2126(16)30193-9. doi:, 10.1016/j.str.2016.06.024. PMID:27568927 doi:http://dx.doi.org/10.1016/j.str.2016.06.024
