Hostname: page-component-78c5997874-8bhkd Total loading time: 0 Render date: 2024-11-17T16:11:50.914Z Has data issue: false hasContentIssue false

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
Get access

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

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

1.Baron, M. D., Davison, M. D., Jones, P. and Critchley, D. R. (1987) The sequence of chick alpha-actinin reveals homologies to spectrin and calmodulin. J. Biol. Chem. 262, 1762317629.Google ScholarPubMed
2.Blanc, E., Zhou, G., Chen, Z., Xie, Q., Tang, J., Wang, J. & Chapman, M. S. (1997). Electron Density Representation and Real Space Refinement (New tricks from an old dog). In Proceedings of the International Union of Crystallography Workshop on Computing Techniques, 1996 (Watenpaugh, K. & Bourne, P., eds.). International Union of Crystallography, San Diego Supercomputer Center, University of Western Washington.Google Scholar
3.Sali, A. and Blundell, T. L. (1993). Comparative protein modelling by satisfaction of spatial restraints. J. Mol. Biol. 234, 779815.CrossRefGoogle ScholarPubMed
4.Taylor, K. A. and Taylor, D. W. (1993) Projection image of smooth muscle alpha-actinin from 2-D crystals formed on positively charged lipid layers. J. Mol. Biol. 230,196205.CrossRefGoogle Scholar
5. Wisconsin Package Version 10.0, Genetics Computer Group (GCG), Madison, Wise.Google Scholar