Professor Jason Chin rewrites genetic code

Trinity Fellow, and Professor of Chemistry and Chemical Biology at Cambridge University, Jason Chin, and his team, have rewritten the genetic code of a common bacteria.  This work heralds the prospect of organisms that can produce new medicines and valuable materials.

The E coli bacteria they have created is the world’s first living organism with entirely synthetic, and radically redesigned, DNA.

Scientists at the MRC Laboratory of Molecular Biology (LMB), led by Professor Chin, refashioned the genetic code of E coli, a bacteria commonly found in the gut of animals and humans, to create an entirely new and simplified genome. This frees up parts of the genetic code for potential therapeutic uses.

DNA contains the instructions that cells need to function. Cells use one key set of  instructions in DNA – called codons – to determine which of 20 amino acids should be combined to form proteins. These ‘building blocks of life’ catalyse a huge range of functions in the body.

All forms of life use 64 codons. Except for the bacteria created by Professor Chin’s team, Syn61, so named for its number of codons.

The fact that the synthetic bacteria are alive, if reproducing more slowly, is a remarkable achievement. It also testament to Professor Chin’s desire to understand why all living organisms encode genetic information in the same way – with multiple codons used for the same amino acid.

Professor Chin, who is Head of both the Division of Protein and Nucleic Acid Chemistry and the Centre for Chemical and Synthetic Biology at the LMB, said:

We have created an organism with a four million base pair synthetic genome that uses only 61 codons to encode protein synthesis. This tells us something fundamental about biology and how malleable the genetic code really is, and also provides exciting new opportunities.

Removing three codons from Syn61, as well as the cellular machinery that reads those codons, might be create virus resistant cells, and – through reassigning the codons to new monomers – enable the genetically encoded synthesis of new materials and therapeutics in cells.

Professor Chin, who was an undergraduate at Oxford, obtained his PhD from Yale, and did post-doctoral work at the Scripps Research Institute in California. Before joining the LMB in 2003, he heard Professor Venki Ramakrishnan, now a Trinity Fellow, describe how he and his team had fathomed the structure and function of the ribosome. Professor Ramakrishnan, currently President of the Royal Society, shared the Nobel Prize in Chemistry in 2009 – a journey he charts in Gene Machine, published in 2018.

‘Venki’s discoveries were a real inspiration for the work we began at LMB’, says Professor Chin, who was recruited to Cambridge by the current Master of Trinity, Sir Gregory Winter, and now heads an international team of students and postdoctoral scientists.

Professor Chin has received many prizes for his prior work, including the Francis Crick Prize from the Royal Society in 2009, the European Molecular Biology Organization’s Gold Medal in 2010 and the Sackler Prize in the Physical Sciences in 2019. He was inducted into the European Inventors Hall of Fame in 2013 and was elected a Fellow of the Academy of Medical Sciences in 2016.