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Cryo-EM 3D Reconstruction of Skeletal Muscle α-Actinin

Published online by Cambridge University Press:  02 July 2020

Jinghua Tang
Affiliation:
Institute of Molecular Biophysics, Florida State University, Tallahassee, FL32306-4380
Dianne W. Taylor
Affiliation:
Institute of Molecular Biophysics, Florida State University, Tallahassee, FL32306-4380
Kenneth A. Taylor
Affiliation:
Institute of Molecular Biophysics, Florida State University, Tallahassee, FL32306-4380
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Extract

α-Actinin is a member of the spectrin superfamily of actin crosslinking proteins. The molecule is an antiparallel homodimer with a polypeptide chain weight of 94-103 kDa. Each chain can be divided into three domains: the N-terminal 250 amino acids forms an actin binding domain, the central domain consisting of four spectrin-like, triple-helical repeats and the Cterminal which contains two EF hand motifs (Baron et al, 1987).

Two models have been proposed for the alignment of the triple helical repeats in the α-actinin structure, an aligned model (Baron et al., 1987) and a staggered model (Taylor and Taylor, 1993). In order to resolve the controversy, we proceeded with the cryo-EM 3D reconstruction from 2D crystal grown on a positively charged lipid monolayer. From rabbit erector spinae aactinin, we obtain better ordered 2D crystals from which we have calculated a 3D reconstruction to ∼15 Å resolution.

Type
Electron Cryomicroscopy of Macromolecules
Copyright
Copyright © Microscopy Society of America

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References

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