Introduction to Syn57
Researchers have developed a novel strain of bacteria featuring a genetic code that is distinct from anything found in the natural world, representing a significant advancement in the field of synthetic biology. The engineered microbe, named Syn57, is an artificial variant of Escherichia coli, a bacterium commonly associated with infections in the gut, urinary tract, and other body parts.
Distinct Genetic Code
Unlike all known forms of life, which utilize 64 codons—three-letter DNA sequences that instruct cells on how to assemble proteins—Syn57 operates with just 57 codons. To visualize this, consider DNA as a cookbook, where each codon serves as a three-letter word that guides the cell in selecting the amino acids, or ‘ingredients,’ needed for protein synthesis.
While organisms typically feature some redundant instructions, Syn57 optimizes its genetic makeup by eliminating these duplicates while maintaining its functionality.
Implications of Syn57
The streamlined codons in Syn57 introduce a plethora of new opportunities, enabling scientists to generate proteins and synthetic compounds that are not found in nature. Additionally, its atypical genetic structure confers resistance against viruses, which depend on the conventional DNA language to invade cells. Moreover, its unique code lessens the risk of hybridization with natural organisms, addressing potential safety concerns.
This breakthrough could facilitate the development of innovative medicines, advanced materials, and synthetic lifeforms that surpass previous natural standards.
Scientific Methodology
To achieve this pivotal transformation, the team fragmented the genome into 38 segments, each approximately 100,000 DNA letters long. They synthesized each piece using yeast and subsequently integrated these segments into E. coli through a technique known as uREXER, which synergizes CRISPR-Cas9 with other methodologies to seamlessly incorporate synthetic DNA.
Some regions of the genome presented challenges, such as slowed growth or resistance to alterations. The researchers overcame these obstacles by refining gene sequences, clarifying overlapping genes, and judiciously selecting which codons to replace.
Functionality and Future Prospects
Through a meticulous assembly process, the fragments were cohesively linked to form the final synthetic bacterium, Syn57, marking it as the most extensively redesigned organism ever created and demonstrating that life can sustain itself with a considerably simplified genetic code.
Wesley Robertson, a synthetic biologist at the Medical Research Council Laboratory in the UK, remarked to the New York Times, ‘We definitely went through these periods where we were like, ‘Well, will this be a dead end, or can we see this through?’ ‘
While Syn57 is viable, its life is fragile. Normal E. coli can reproduce every hour, but Syn57 takes four hours to do so, making it ‘extremely feeble,’ according to Yonatan Chemla, a synthetic biologist at MIT who was not part of the research team. The bacteria exhibit growth on a jelly-like surface and in a nutrient-rich liquid, although at a rate four times slower than their natural counterparts.
Dr. Robertson and his colleagues are currently conducting experiments to determine whether they can enhance its growth rate. If successful, scientists might be able to program Syn57 to perform tasks that typical bacteria cannot achieve.
Potential Applications
In addition to the 20 standard amino acids utilized by all known life forms for protein synthesis, chemists can design hundreds of additional amino acids. The seven missing codons in Syn57 could potentially be repurposed to align with these synthetic amino acids, enabling the bacterium to generate new pharmaceuticals or other beneficial compounds.
Furthermore, Syn57 may contribute to creating engineered microbes that are more environmentally friendly. As microbes are adept at exchanging genes, this characteristic poses risks when it comes to the dispersion of engineered DNA. However, a gene derived from Syn57 would be incomprehensible to natural bacteria due to its unique genetic language, safeguarding it from use beyond laboratory confines.
