What if our Genetic Code Could Have Six Rather than 4 Nucleotides?

Why did nature decide to create our genetic code with only four letters?  Dr. Steven Benner at the Foundation for Applied Molecular Evolution in Florida has been researching this question for nearly 30 years.  Over this time Benner has spent his time theorizing and attempting to synthesize DNA and RNA with more than four nucleotides to increase its capabilities.  Recently his research team has successfully synthesized two synthetic nucleotides that they have deemed “P” and “Z”.  These nucleotides have the unique ability to fit into DNA’s helical sequence seamlessly allowing a glimpse into the possibilities of a six letter genetic alphabet. (1)

Benner’s six-nucleotide alphabet has shown tremendous upside in the realm of genetics. Normally our bodies only have the ability to synthesize 20 amino acids using the standard nucleotides ATCG.  Using a six-letter alphabet, it would be theoretically possibly to now synthesize up to 216 amino acids, which would allow the creation of unprecedented genes and functions throughout an organism.  Benner also continues to state that with continued engineering,, he believes a six nucleotide alphabet could even one day allow the RNA of a genome to function at a high enough level to eliminate the need for proteins as we know it.

There is no question that many more years of research are needed to adequately study Banner’s accomplishments and their future implications in genetics.  However, the infant stages of his novel research have already begun to shed light on the vast possibilities that an enhanced genome may possess.  Also, Banner doesn’t intend on accepting satisfaction from achieving his initial 6-nucleotide goal.   He has greater plans to work on the synthesis of a 10 or even 12 letter alphabet that would truly turn the world of genetics as we know it upside down.  Although Benner's plan sounds terrific on the surface, what are some potential hurdles or problems that this new science may encounter?     

Citations

Article originally viewed on “FlipBoard” and Quanta Magazine

https://www.quantamagazine.org/20150710-genetic-alphabet/

1. Georgiadis MM, Singh I, Kellett WF, Hoshika S, Benner SA, Richards NG. Structural basis for a six nucleotide genetic alphabet. J Am Chem Soc. 2015 Jun 3;137(21):6947-55. doi: 10.1021/jacs.5b03482. Epub 2015 May 18. PubMed PMID: 25961938.