The use of artificial structure as an initial reference model for projection-matching three dimensional reconstruction: visualization of macromolecular structure using cryo-electron microscopy

Projection-matching single particle three dimensional reconstruction following to electron microscopy is the one of common methods to visualize three dimensional structures of target macromolecules or protein-protein interaction at medium or near-atomic resolution. In this report, we demonstrated the potentiality of using artificial structure as an initial reference model for its computational processing by describing an example experiment in which we obtained ~ 2000 single particle images from cryo-electron microscopy. The reconstruction using the model provided correct matching parameters of single particle experimental images with projection images of the model, ultimately resulting in generating informative three dimensional volume. Comparative analysis confirmed that the resultant volume has a remarkably similar structure to the proposed atomic model. These results provided suggestive evidence for using this technical approach as a useful analytical tool for determining macromolecular structure in the model independence way. In addition, the finding goal can be used for evaluating high resolution structure processed from the reference model of atomic structure since it is an ideal method to eliminate any possibilities of model-bias.