Cambridge researchers have redesigned the genetic code of microorganisms to create a synthetic cell with abilities different from those in nature, opening up the possibility of new materials for everything from plastics to antibiotics.
The knowledge of how to manipulate and edit DNA at the core of all genetic processes has been established, but until now it has not been possible to change the code 3 billion years ago, through which DNA directs cells to form chains of amino acids to form the working molecules of life.
“This may be a revolution in biology,” said Jason Chin, project leader of the MRC Molecular Biology Laboratory.
“These bacteria may become renewable and programmable factories to produce a variety of new molecules with new properties, which may be beneficial to biotechnology and medicine, including the manufacture of new drugs such as antibiotics.”
Landmark research published in the journal science, Built on the team in 2019 breakthrough Created a common version Escherichia coli The gut microbes and all their DNA (called the genome) are constructed entirely of laboratory chemicals.
Scientists have now rewritten the genetic code of the new Syn61 bacteria, which not only changes the DNA, but also changes the cellular mechanism that transforms genes into biochemical products.This creates a new organism that looks like Escherichia coli But it has additional attributes.
The key to this process is the set of three biochemical “letters” in DNA-A, T, C, and G. Each of these “codons” tells the cell to add specific amino acids to the growing protein chain. Since the birth of the earth, all living things have stored genetic information in this way.
Because there are 64 possible codons and only 20 naturally occurring amino acids, the genetic code has a lot of redundancy. Scientists at the University of Cambridge took advantage of this by reusing some codons to create different building blocks that do not exist in nature, while still allowing cells to make all the proteins needed for life.
An analogy is to think of nature’s genetic code as an English computer keyboard, in which certain letters appear more than once. In fact, the Cambridge team has converted the repeated A into the Greek letter alpha, the remaining B into the beta, etc., making it possible to input Greek and English.
Experiments have shown that modified bacterial cells can connect foreign monomers (molecular building blocks) together to form new proteins and other macromolecules called polymers.
“We hope to use these bacteria to discover and build long synthetic polymers that fold into structures and may form new material categories,” Chin proposed, adding that another application would be new types of polymers, such as biodegradable plastics. .
Delilah Jewel and Abhishek Chatterjee of Boston College, two leading scientists who did not participate in the Cambridge research, said that the use of “non-natural building blocks” technology will open countless new applications, “from the development of new biotherapeutics to biomaterials with innovative properties. “
One aspect of this technology is that synthetic bacteria are not affected by viral infections, which require natural genetic processes to replicate in host cells.
“If the virus enters the bacterial vat used to make certain drugs, then it can destroy the entire batch of drugs,” Chin explained. “Our modified bacterial cells can overcome this problem by completely resisting the virus.”
Chin emphasized the “huge commercial potential” of the microbial engineering process and added that negotiations to protect intellectual property rights have already taken place.