5v7x
From Proteopedia
Crystal Structure of Myosin 1b residues 1-728 with bound sulfate and Calmodulin
Structural highlights
Disease[CALM1_HUMAN] The disease is caused by mutations affecting the gene represented in this entry. Mutations in CALM1 are the cause of CPVT4. The disease is caused by mutations affecting the gene represented in this entry. Mutations in CALM1 are the cause of LQT14. Function[MYO1B_RAT] Motor protein that may participate in process critical to neuronal development and function such as cell migration, neurite outgrowth and vesicular transport (By similarity). [CALM1_HUMAN] Calmodulin mediates the control of a large number of enzymes, ion channels, aquaporins and other proteins through calcium-binding. Among the enzymes to be stimulated by the calmodulin-calcium complex are a number of protein kinases and phosphatases. Together with CCP110 and centrin, is involved in a genetic pathway that regulates the centrosome cycle and progression through cytokinesis (PubMed:16760425). Mediates calcium-dependent inactivation of CACNA1C (PubMed:26969752). Positively regulates calcium-activated potassium channel activity of KCNN2 (PubMed:27165696).[1] [2] [3] [4] Publication Abstract from PubMedMyosins adjust their power outputs in response to mechanical loads in an isoform-dependent manner, resulting in their ability to dynamically adapt to a range of motile challenges. Here, we reveal the structural basis for force-sensing based on near-atomic resolution structures of one rigor and two ADP-bound states of myosin-IB (myo1b) bound to actin, determined by cryo-electron microscopy. The two ADP-bound states are separated by a 25 degrees rotation of the lever. The lever of the first ADP state is rotated toward the pointed end of the actin filament and forms a previously unidentified interface with the N-terminal subdomain, which constitutes the upper half of the nucleotide-binding cleft. This pointed-end orientation of the lever blocks ADP release by preventing the N-terminal subdomain from the pivoting required to open the nucleotide binding site, thus revealing how myo1b is inhibited by mechanical loads that restrain lever rotation. The lever of the second ADP state adopts a rigor-like orientation, stabilized by class-specific elements of myo1b. We identify a role for this conformation as an intermediate in the ADP release pathway. Moreover, comparison of our structures with other myosins reveals structural diversity in the actomyosin binding site, and we reveal the high-resolution structure of actin-bound phalloidin, a potent stabilizer of filamentous actin. These results provide a framework to understand the spectrum of force-sensing capacities among the myosin superfamily. High-resolution cryo-EM structures of actin-bound myosin states reveal the mechanism of myosin force sensing.,Mentes A, Huehn A, Liu X, Zwolak A, Dominguez R, Shuman H, Ostap EM, Sindelar CV Proc Natl Acad Sci U S A. 2018 Jan 22. pii: 1718316115. doi:, 10.1073/pnas.1718316115. PMID:29358376[5] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See AlsoReferences
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Categories: Large Structures | Dominguez, R | Ostap, E M | Shuman, H | Zwolak, A | Actin | Calmodulin | Force | Motor | Motor protein | Myosin | Unconventional
