2VAY

Calmodulin complexed with CaV1.1 IQ peptide

Summary for 2VAY

• Entry DOI: 10.2210/pdb2vay/pdb
• Related: 1AJI 1CDL 1CLL 1CTR 1IWQ 1J7O 1J7P 1K90 1K93 1L7Z 1LVC 1NKF 1PK0 1S26 1SK6 1SW8 1WRZ 1XFU 1XFV 1XFW 1XFX 1XFY 1XFZ 1Y6W 1YR5 1YRT 1YRU 1ZOT 2BE6 2F3Y 2F3Z 2V01 2V02
• Descriptor: CALMODULIN, VOLTAGE-DEPENDENT L-TYPE CALCIUM CHANNEL SUBUNIT ALPHA-1S, CALCIUM ION, ... (5 entities in total)
• Functional Keywords: excitation-contraction coupling, metal transport, cav, calcium, transport, acetylation, methylation, l-type calcium channel, dihydropyridine receptor, ionic channel, ion transport, transmembrane, phosphorylation, alpha-1s subunit, calcium transport, ubl conjugation, calcium channel, skeletal muscle, voltage-dependent, voltage-gated channel
• Biological source: HOMO SAPIENS (HUMAN); More
• Total number of polymer chains: 2
• Total formula weight: 19514.20

Authors

Halling, D.B.,Black, D.J.,Pedersen, S.E.,Hamilton, S.L. (deposition date: 2007-09-05, release date: 2008-09-16, Last modification date: 2023-12-13)

Primary citation

Halling, D.B.,Georgiou, D.K.,Black, D.J.,Yang, G.,Fallon, J.L.,Quiocho, F.A.,Pedersen, S.E.,Hamilton, S.L.
Determinants in Cav1 Channels that Regulate the Ca2+ Sensitivity of Bound Calmodulin.
J.Biol.Chem., 284:20041-, 2009

PubMed Abstract: Calmodulin binds to IQ motifs in the alpha(1) subunit of Ca(V)1.1 and Ca(V)1.2, but the affinities of calmodulin for the motif and for Ca(2+) are higher when bound to Ca(V)1.2 IQ. The Ca(V)1.1 IQ and Ca(V)1.2 IQ sequences differ by four amino acids. We determined the structure of calmodulin bound to Ca(V)1.1 IQ and compared it with that of calmodulin bound to Ca(V)1.2 IQ. Four methionines in Ca(2+)-calmodulin form a hydrophobic binding pocket for the peptide, but only one of the four nonconserved amino acids (His-1532 of Ca(V)1.1 and Tyr-1675 of Ca(V)1.2) contacts this calmodulin pocket. However, Tyr-1675 in Ca(V)1.2 contributes only modestly to the higher affinity of this peptide for calmodulin; the other three amino acids in Ca(V)1.2 contribute significantly to the difference in the Ca(2+) affinity of the bound calmodulin despite having no direct contact with calmodulin. Those residues appear to allow an interaction with calmodulin with one lobe Ca(2+)-bound and one lobe Ca(2+)-free. Our data also provide evidence for lobe-lobe interactions in calmodulin bound to Ca(V)1.2.

PubMed: 19473981
DOI: 10.1074/JBC.M109.013326

Experimental method

X-RAY DIFFRACTION (1.94 Å)