quasisymmetry

English

Etymology

quasi- +‎ symmetry

Noun

quasisymmetry (countable and uncountable, plural quasisymmetries)

1. (mathematics) A mapping that preserves shape but allows size to change in a well-defined manner.
2. (biology) A pattern in which many copies of a viral protein form a huge spherical coating, where each subunit has an almost symmetrical arrangement with its neighbors.
   • 2013, G.E. Schulz, R.H. Schirmer, Principles of Protein Structure, page 99:

     So-called “quasisymmetry” occurs if all subunits are chemically identical but have two slightly different conformations so that slightly different contacts can be made.

   • 2016, David S. Goodsell, Atomic Evidence: Seeing the Molecular Basis of Life, page 72:

     Evolution blindly explores every possibility, and as more and more structures of viral capsids have been studied, numerous exceptions to classic quasisymmetry have been found.