1s5g
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Structure of Scallop myosin S1 reveals a novel nucleotide conformation
OverviewOverview
Structural studies of myosin have indicated some of the conformational, changes that occur in this protein during the contractile cycle, and we, have now observed a conformational change in a bound nucleotide as well., The 3.1-A x-ray structure of the scallop myosin head domain (subfragment, 1) in the ADP-bound near-rigor state (lever arm =45 degrees to the helical, actin axis) shows the diphosphate moiety positioned on the surface of the, nucleotide-binding pocket, rather than deep within it as had been observed, previously. This conformation strongly suggests a specific mode of entry, and exit of the nucleotide from the nucleotide-binding pocket through the, so-called "front door." In addition, using a variety of scallop, structures, including a relatively high-resolution 2.75-A nucleotide-free, near-rigor structure, we have identified a conserved complex salt bridge, connecting the 50-kDa upper and N-terminal subdomains. This salt bridge is, present only in crystal structures of muscle myosin isoforms that exhibit, a strong reciprocal relationship (also known as coupling) between actin, and nucleotide affinity.
About this StructureAbout this Structure
1S5G is a Protein complex structure of sequences from Argopecten irradians with SO4, CA, MG and ADP as ligands. Full crystallographic information is available from OCA.
ReferenceReference
Myosin subfragment 1 structures reveal a partially bound nucleotide and a complex salt bridge that helps couple nucleotide and actin binding., Risal D, Gourinath S, Himmel DM, Szent-Gyorgyi AG, Cohen C, Proc Natl Acad Sci U S A. 2004 Jun 15;101(24):8930-5. Epub 2004 Jun 7. PMID:15184651
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