A hypothesis about myosin catalysis.

Hirofumi Onishi; Takashi Ohki; Naoki Mozhizuki; Manuel F Morales

doi:10.1007/978-1-4419-9029-7_16

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PubMed · 15098665

A hypothesis about myosin catalysis.

Hirofumi Onishi·Takashi Ohki·Naoki Mozhizuki·Manuel F Morales

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Abstract

When ATP binds to the active site of myosin heads, Switch II undergoes a large conformational change and the cleft surrounding the bound gamma-phosphate closes. In the closed state, Glu470 in Switch II comes together with Arg247 in Switch I to form a salt-bridge. Here, the functional significance of the two bridging residues was tested by using site-directed mutagenesis. We conclude from such tests that (a) the attractive force between Arg247 and the gamma-phosphate of ATP moves the cleft to close, and (b) during hydrolysis, Glu470 is intimately involved in positioning the lytic water for the attack on the gamma-phosphorus. We also speculate on how the salt-bridge between Arg247 and Glu470 is related to hydrolysis.

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Actins Adenosine Triphosphatases Adenosine Triphosphate Animals Arginine Binding Sites Catalysis Dictyostelium Glutamic Acid Hydrolysis Models, Chemical Models, Molecular Mutagenesis, Site-Directed Myosins Phosphates Protein Binding Protein Conformation Salts Journal Article

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Hirofumi Onishi, Takashi Ohki, Naoki Mozhizuki, Manuel F Morales. 2003. A hypothesis about myosin catalysis.. https://doi.org/10.1007/978-1-4419-9029-7_16

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