Correction for Sitar et al., Molecular architecture of the Spire-actin nucleus and its implication for actin filament assembly.

Abstract

The Spire protein is a multifunctional regulator of actin assembly. We studied the structures and properties of Spire-actin complexes by X-ray scattering, X-ray crystallography, total internal reflection fluorescence microscopy, and actin polymerization assays. We show that Spire-actin complexes in solution assume a unique, longitudinal-like shape, in which Wiskott-Aldrich syndrome protein homology 2 domains (WH2), in an extended configuration, line up actins along the long axis of the core of the Spire-actin particle. In the complex, the kinase noncatalytic C-lobe domain is positioned at the side of the first N-terminal Spire-actin module. In addition, we find that preformed, isolated Spire-actin complexes are very efficient nucleators of polymerization and afterward dissociate from the growing filament. However, under certain conditions, all Spire constructs--even a single WH2 repeat--sequester actin and disrupt existing filaments. This molecular and structural mechanism of actin polymerization by Spire should apply to other actin-binding proteins that contain WH2 domains in tandem.

DOI: 10.1073/pnas.1115465108

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Cite this paper

@article{Sitar2011CorrectionFS, title={Correction for Sitar et al., Molecular architecture of the Spire-actin nucleus and its implication for actin filament assembly.}, author={Tomasz Sitar and Julia O. Gallinger and Anna M Ducka and Teemu P Ikonen and Michael Wohlhoefler and Kurt M. Schmoller and Andreas R. Bausch and Peteranne B. Joel and Kathleen M Trybus and Angelika A. Noegel and Michael Schleicher and Robert Huber and Tad A. Holak}, journal={Proceedings of the National Academy of Sciences of the United States of America}, year={2011}, volume={108 49}, pages={19575-80} }