Sandbox Reserved 930: Difference between revisions
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{{Sandbox_Reserved_510042_1}} | {{Sandbox_Reserved_510042_1}} | ||
=Scallop myosin head in detached state= | =Scallop myosin head in the detached state= | ||
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Taking part in the organization of the different conformations of the contractile cycle is also the so called switch I, which is a second catalytic loop of the nucleotide-binding pocket. <ref name="houdusse2000"> PMID: 11016966</ref> Switch II forms a specific salt bridge and hydrogen bond interactions with switch I that stabilize the pre-power stroke state <ref name="himmel2002"> PMID: 12297624</ref>. | Taking part in the organization of the different conformations of the contractile cycle is also the so called switch I, which is a second catalytic loop of the nucleotide-binding pocket. <ref name="houdusse2000"> PMID: 11016966</ref> Switch II forms a specific salt bridge and hydrogen bond interactions with switch I that stabilize the pre-power stroke state <ref name="himmel2002"> PMID: 12297624</ref>. | ||
In the | In the detached conformation of the MD, switch II interacts with the nucleotide-binding pocket and forms the stabilizing hydrogen bond interactions and a salt bridge with switch I <ref name="himmel2002"> PMID: 12297624</ref><ref name="risal2004"> PMID: 15184651</ref>. Rotation of the 50-kDa upper subdomain away from the N-terminal subdomain pulls switches I and II apart breaking the protein- nucleotide interactions between switch I and ADP, as well as changing the conformation of switch II. These changes result in closing of the actin-binding site and opening of the nucleotide-binding pocket, leading to MgADP release. At the same time SH1 helix is unwound and the lever arm is able to change its position enabling sliding of myosin through the actin filament <ref name="himmel2002"> PMID: 12297624</ref>. | ||
