On the optimality of the standard genetic code: the role of stop codons

TL;DR

This paper investigates the optimality of the standard genetic code's stop codon assignments, demonstrating its maximal stability against certain mutations and its near-optimality among all possible configurations.

Contribution

It provides a mathematical analysis showing the standard genetic code's stop codon assignment is highly optimal for mutation stability, with only a small fraction of configurations being equally optimal.

Findings

The standard genetic code's stop codons maximize stability against frameshift and nonsense mutations.

Only about 1.3% of all possible stop codon assignments are optimal.

The standard code has the maximum number of optimal configurations among those with three stop codons.

Abstract

The genetic code markup is the assignment of stop codons. The standard genetic code markup ensures the maximum possible stability of genetic information with respect to two fault classes: frameshift and nonsense mutations. There are only 528 (about 1,3% of total number) optimal markups in the set of markups having 3 stop codons. Among the sets of markups with 1,2,...,8 stop codons, the standard case having 3 stop codons has maximum absolute number of optimal markups.