The structure of nonvertebrate actin: Implications for the ATP hydrolytic mechanism

The structures of Saccharomyces cerevisiae , Dictyostelium , and Caenorhabditis elegans actin bound to gelsolin segment-1 have been solved and refined at resolutions between 1.9 and 1.75 Å. These structures reveal several features relevant to the ATP hydrolytic mechanism, including identification of the nucleophilic water and the roles of Gln-137 and His-161 in positioning and activating the catalytic water, respectively. The involvement of...