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bioRxiv · 10.1101/2020.08.26.268748

Cryo-electron microscopy structures of pyrene-labeled ADP-Pi- and ADP-actin filaments

Chou, S. Z.·Pollard, T. D.
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Abstract

We report high resolution cryo-electron microscopy structures of actin filaments with N-1-pyrene conjugated to cysteine 374 and either ADP (3.2 [A]) or ADP-phosphate (3.0 [A]) in the active site. Polymerization buries pyrene in a hydrophobic cavity between subunits along the long-pitch helix with only minor differences in conformation compared with native actin filaments. These structures explain how polymerization increases the fluorescence 20-fold, how myosin and cofilin binding to filaments reduces the fluorescence and how profilin binding to actin monomers increases the fluorescence.

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Chou, S. Z., Pollard, T. D.. 2020-08-26. Cryo-electron microscopy structures of pyrene-labeled ADP-Pi- and ADP-actin filaments. https://doi.org/10.1101/2020.08.26.268748

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