Extended Data Fig. 7: High-resolution structures of β-actin variants R183W and N111S.
From: Molecular mechanisms of inorganic-phosphate release from the core and barbed end of actin filaments
a, b, Structures of F-actin-R183W (a) and F-actin-N111S (b) shown as cartoon orthogonal to the filament axis. The central subunits are colored gold and blue, respectively. Water molecules modeled in both structures are depicted as red spheres. The pointed and barbed end directions are annotated, as well as the helical rise and twist of both mutant structures. c, Cryo-EM densities and fitted atomic models for selected regions of both reconstructions. Specifically, amino-acid environments near the mutated residues are shown to highlight differences between both structures. d, Alignment of single subunits of filamentous wild-type α-actin (pdb 8a2t, colored green), R183W-β-actin (gold) and N111S-β-actin (blue) in the Mg2+-ADP state. The F-actin subdomains and regions important for Pi release are annotated. e, Nucleotide arrangement in high-resolution Mg2+-ADP-bound F-actin structures of wild-type α-actin (pdb 8a2t, left), β-actin-R183W (middle) and β-actin-N111S (right). The arrangements in wild-type α-actin and β-actin-N111S are similar, whereas the Mg2+ ion adopts a different position in the β-actin-R183W structure.
