2f3y
Calmodulin/IQ domain complex
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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.
DiseaseDisease
Known diseases associated with this structure: Cavernous malformations of CNS and retina OMIM:[604214], Cerebral cavernous malformations-1 OMIM:[604214], Hyperkeratotic cutaneous capillary-venous malformations associated with cerebral capillary malformations OMIM:[604214], Leukemia, acute T-cell lymphoblastic OMIM:[603025], Leukemia, acute myeloid OMIM:[603025], Timothy syndrome OMIM:[114205]
About this StructureAbout this Structure
2F3Y is a Protein complex structure of sequences from Homo sapiens with CA and MG as ligands. 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
Page seeded by OCA on Mon Nov 12 21:59:23 2007