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3etq

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X-ray structure of cysteine-free fragment of mHCN2 C-terminal region from amino acids 443-630 including C508N, C584S, and C601S mutations

Structural highlights

3etq is a 2 chain structure with sequence from Mus musculus. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance.
Method:	X-ray diffraction, Resolution 1.9Å
Ligands:
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]

Evolutionary Conservation

Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf.

Publication Abstract from PubMed

Visualizing conformational dynamics in proteins has been difficult, and the atomic-scale motions responsible for the behavior of most allosteric proteins are unknown. Here we report that fluorescence resonance energy transfer (FRET) between a small fluorescent dye and a nickel ion bound to a dihistidine motif can be used to monitor small structural rearrangements in proteins. This method provides several key advantages over classical FRET, including the ability to measure the dynamics of close-range interactions, the use of small probes with short linkers, a low orientation dependence, and the ability to add and remove unique tunable acceptors. We used this 'transition metal ion FRET' approach along with X-ray crystallography to determine the structural changes of the gating ring of the mouse hyperpolarization-activated cyclic nucleotide-regulated ion channel HCN2. Our results suggest a general model for the conformational switch in the cyclic nucleotide-binding site of cyclic nucleotide-regulated ion channels.

Mapping the structure and conformational movements of proteins with transition metal ion FRET.,Taraska JW, Puljung MC, Olivier NB, Flynn GE, Zagotta WN Nat Methods. 2009 Jul;6(7):532-7. Epub 2009 Jun 14. PMID:19525958^[2]

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

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
↑ Taraska JW, Puljung MC, Olivier NB, Flynn GE, Zagotta WN. Mapping the structure and conformational movements of proteins with transition metal ion FRET. Nat Methods. 2009 Jul;6(7):532-7. Epub 2009 Jun 14. PMID:19525958 doi:10.1038/nmeth.1341