2f3y
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| , resolution 1.450Å | |||||||
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| Ligands: | , | ||||||
| Gene: | calm1, calm2, calm3 (Homo sapiens) | ||||||
| Related: | 1CDL, 1CDM, 1PRW
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| Resources: | FirstGlance, OCA, PDBsum, RCSB | ||||||
| Coordinates: | save as pdb, mmCIF, xml | ||||||
Calmodulin/IQ domain complex
OverviewOverview
Ca2+-dependent inactivation (CDI) and facilitation (CDF) of the Ca(v)1.2 Ca2+ channel require calmodulin binding to a putative IQ motif in the carboxy-terminal tail of the pore-forming subunit. We present the 1.45 A crystal structure of Ca2+-calmodulin bound to a 21 residue peptide corresponding to the IQ domain of Ca(v)1.2. This structure shows that parallel binding of calmodulin to the IQ domain is governed by hydrophobic interactions. Mutations of residues I1672 and Q1673 in the peptide to alanines, which abolish CDI but not CDF in the channel, do not greatly alter the structure. Both lobes of Ca2+-saturated CaM bind to the IQ peptide but isoleucine 1672, thought to form an intramolecular interaction that drives CDI, is buried. These findings suggest that this structure could represent the conformation that calmodulin assumes in CDF.
About this StructureAbout this Structure
2F3Y is a Protein complex structure of sequences from Homo sapiens. Full crystallographic information is available from OCA.
ReferenceReference
Structure of calmodulin bound to the hydrophobic IQ domain of the cardiac Ca(v)1.2 calcium channel., Fallon JL, Halling DB, Hamilton SL, Quiocho FA, Structure. 2005 Dec;13(12):1881-6. PMID:16338416
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