A new study suggests that while it is possible to expand the number of nucleotides within codons, the resulting complexity leads to inefficiencies that help explain why such extended codons don't exist, according to a report in Quanta Magazine.
In a study appearing in eLife, researchers from the Massachusetts Institute of Technology and Yale University engineered E. coli to have four-nucleotide codons instead of the usual three. While these altered bacteria could successfully translate these quadruplet codons, they did so inefficiently, Quanta reports, adding that the study's authors concluded that the reason why nature didn't select for a quadruplet code wasn't because it was unachievable, but rather because the triplet code was simple and sufficient.