3pn7

Visualizing new hinges and a potential major source of compliance in the lever arm of myosin

spinqualitylabelsall models 3pn7, resolution 2.25Å Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image   Print3D Structural highlights 3pn7 is a 6 chain structure with sequence from Placopecten magellanicus. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance. Method: X-ray diffraction, Resolution 2.25Å Ligands: CA, MG Resources: FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT Function Q26080_PLAMG Publication Abstract from PubMed We have determined the 2.3-A-resolution crystal structure of a myosin light chain domain, corresponding to one type found in sea scallop catch ("smooth") muscle. This structure reveals hinges that may function in the "on" and "off" states of myosin. The molecule adopts two different conformations about the heavy chain "hook" and regulatory light chain (RLC) helix D. This conformational change results in extended and compressed forms of the lever arm whose lengths differ by 10 A. The heavy chain hook and RLC helix D hinges could thus serve as a potential major and localized source of cross-bridge compliance during the contractile cycle. In addition, in one of the molecules of the crystal, part of the RLC N-terminal extension is seen in atomic detail and forms a one-turn alpha-helix that interacts with RLC helix D. This extension, whose sequence is highly variable in different myosins, may thus modulate the flexibility of the lever arm. Moreover, the relative proximity of the phosphorylation site to the helix D hinge suggests a potential role for conformational changes about this hinge in the transition between the on and off states of regulated myosins. Visualizing key hinges and a potential major source of compliance in the lever arm of myosin.,Brown JH, Senthil Kumar VS, O'Neall-Hennessey E, Reshetnikova L, Robinson H, Nguyen-McCarty M, Szent-Gyorgyi AG, Cohen C Proc Natl Acad Sci U S A. 2010 Dec 13. PMID:21149681 From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See Also Myosin 3D Structures

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