Cryoelectron-Microscopy Image Reconstruction of Symmetry Mismatches in Bacteriophage φ29

Marc C. Morais, Yizhi Tao, Norman H. Olson, Shelley Grimes, Paul J. Jardine, Dwight L. Anderson, Timothy S. Baker, Michael G. Rossmann
2001 Journal of Structural Biology  
A method has been developed for three-dimensional image reconstruction of symmetry-mismatched components in tailed phages. Although the method described here addresses the specific case where differing symmetry axes are coincident, the method is more generally applicable, for instance, to the reconstruction of images of viral particles that deviate from icosahedral symmetry. Particles are initially oriented according to their dominant symmetry, thus reducing the search space for determining the
more » ... orientation of the less dominant, symmetry-mismatched component. This procedure produced an improved reconstruction of the sixfoldsymmetric tail assembly that is attached to the fivefold-symmetric prolate head of 29, demonstrating that this method is capable of detecting and reconstructing an object that included a symmetry mismatch. A reconstruction of 29 prohead particles using the methods described here establishes that the pRNA molecule has fivefold symmetry when attached to the prohead, consistent with its proposed role as a component of the stator in the 29 DNA packaging motor.
doi:10.1006/jsbi.2001.4379 pmid:11562164 pmcid:PMC5595366 fatcat:4kluevoklfa6npcuvp6n5brskq