Related Experiment Video
Updated: Aug 15, 2026

Structure of HIV-1 Capsid Assemblies by Cryo-electron Microscopy and Iterative Helical Real-space Reconstruction
Published on: August 9, 2011
I-symmetry, the highest chiral point group, and the icosahedral structure of virus particles
1Department of Chemistry Ben-Gurion University of the Negev Be'er-Sheva, Israel.
Abstract:
Small molecules exhibiting I-symmetry, the member of highest order amongst the five chiral point groups, have yet to be made. However, many virus particles such as the human adenovirus exhibit icosahedral symmetry. The handedness of the subunits being exchanged or permutated by symmetry operations in these supramolecular structures remain invariant since their protein constituents contain L-amino acids. This is only consistent with the existence of symmetry operations of the first kind, and thus these chiral icosahedral ensembles provide suitable examples of I-symmetry.
Related Concept Videos
Viral Structure
Chirality
Chiral objects exhibit a sense of handedness when they interact with another chiral object. For example, our left foot can only fit in the left shoe and not in the right shoe. Achiral objects — objects that have...
Chirality at Nitrogen, Phosphorus, and Sulfur
A consequence of chirality is the need for enantiomeric resolution. While this is theoretically possible for all...
Symmetry Elements in a Crystal
The Seven Crystal Systems: Overview
Crystallographic Point Groups

