Crystal Structure of Apo-Calmodulin Bound to the First Two Iq Motifs of Myosin V Reveals Essential Recognition Features.Houdusse, A., Gaucher, J.F., Krementsova, E., Mui, S., Trybus, K.M., Cohen, C.
(2006) Proc Natl Acad Sci U S A 103: 19326
- PubMed: 17151196
- DOI: https://doi.org/10.1073/pnas.0609436103
- Primary Citation of Related Structures:
- PubMed Abstract:
A 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.
Motilité Structurale, Institut Curie, Centre National de la Recherche Scientifique, Unite Mixté de Recherche 144, 26 rue d'Ulm, 75248, Paris Cedex 05, France.