Proteins are composed of 20 amino acids. Those amino acids are determined by a total of 64 codons. Three base pairs of the DNA, also named a codon, are encoding one amino acid. Eighteen amino acids contain more than one codon, which can have an impact on gene-expression.
In this study, an Escherichia coli strain with a completely synthetic genome was described in which 3 codons were removed from the entire genome so that it only has 61 codons. The E. coli strain was named “Syn61” and contains 4 mega base pairs, making it the biggest synthetically generated genome to date. Syn61 bacteria proliferate more slowly compared to the original strain, are larger in size and produce proteins differently. The scientists want to use Syn61-bacteria for the production of biopolymers in the future.
Fredens, J., Wang, K., de la Torre, D., Funke, L. F. H., Robertson, W. E., Christova, Y., Chin, J. W. (2019). Total synthesis of Escherichia coli with a recoded genome. Nature. doi: 10.1038/s41586-019-1192-5