2ix7

Publication Abstract from PubMed

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.

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.