2ix7
Structure of apo-calmodulin bound to unconventional myosin VStructure of apo-calmodulin bound to unconventional myosin V
Structural highlights
FunctionCALM1_MOUSE Calmodulin acts as part of a calcium signal transduction pathway by mediating the control of a large number of enzymes, ion channels, aquaporins and other proteins through calcium-binding. Calcium-binding is required for the activation of calmodulin. Among the enzymes to be stimulated by the calmodulin-calcium complex are a number of protein kinases, such as myosin light-chain kinases and calmodulin-dependent protein kinase type II (CaMK2), and phosphatases. Together with CCP110 and centrin, is involved in a genetic pathway that regulates the centrosome cycle and progression through cytokinesis. Is a regulator of voltage-dependent L-type calcium channels. Mediates calcium-dependent inactivation of CACNA1C. Positively regulates calcium-activated potassium channel activity of KCNN2. Forms a potassium channel complex with KCNQ1 and regulates electrophysiological activity of the channel via calcium-binding. Acts as a sensor to modulate the endoplasmic reticulum contacts with other organelles mediated by VMP1:ATP2A2.[UniProtKB:P0DP23] 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 PubMedA 2.5-A resolution structure of calcium-free calmodulin (CaM) bound to the first two IQ motifs of the murine myosin V heavy chain reveals an unusual CaM conformation. The C-terminal lobe of each CaM adopts a semi-open conformation that grips the first part of the IQ motif (IQxxxR), whereas the N-terminal lobe adopts a closed conformation that interacts more weakly with the second part of the motif (GxxxR). Variable residues in the IQ motif play a critical role in determining the precise structure of the bound CaM, such that even the consensus residues of different motifs show unique interactions with CaM. This complex serves as a model for the lever arm region of many classes of unconventional myosins, as well as other IQ motif-containing proteins such as neuromodulin and IQGAPs. Crystal structure of apo-calmodulin bound to the first two IQ motifs of myosin V reveals essential recognition features.,Houdusse A, Gaucher JF, Krementsova E, Mui S, Trybus KM, Cohen C Proc Natl Acad Sci U S A. 2006 Dec 19;103(51):19326-31. Epub 2006 Dec 6. PMID:17151196[1] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See AlsoReferences |
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