1dfl
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SCALLOP MYOSIN S1 COMPLEXED WITH MGADP:VANADATE-TRANSITION STATE
OverviewOverview
We have determined the structure of the intact scallop myosin head, containing both the motor domain and the lever arm, in the nucleotide-free, state and in the presence of MgADP.V04, corresponding to the transition, state. These two new structures, together with the previously determined, structure of scallop S1 complexed with MgADP (which we interpret as a, detached ATP state), reveal three conformations of an intact S1 obtained, from a single isoform. These studies, together with new crystallization, results, show how the conformation of the motor depends on the nucleotide, content of the active site. The resolution of the two new structures (, approximately 4 A) is sufficient to establish the relative positions of, the subdomains and the overall conformation of the joints within the motor, domain as well as the position of the lever arm. Comparison of available, crystal structures from different myosin isoforms and truncated constructs, in either the nucleotide-free or transition states indicates that the, major features within the motor domain are relatively invariant in both, these states. In contrast, the position of the lever arm varies, significantly between different isoforms. These results indicate that the, heavy-chain helix is pliant at the junction between the converter and the, lever arm and that factors other than the precise position of the, converter can influence the position of the lever arm. It is possible that, this pliant junction in the myosin head contributes to the compliance, known to be present in the crossbridge.
About this StructureAbout this Structure
1DFL is a Protein complex structure of sequences from Argopecten irradians with CA, MG, VO4 and ADP as ligands. Full crystallographic information is available from OCA.
ReferenceReference
Three conformational states of scallop myosin S1., Houdusse A, Szent-Gyorgyi AG, Cohen C, Proc Natl Acad Sci U S A. 2000 Oct 10;97(21):11238-43. PMID:11016966
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