Antarctic microbes yield rare amino acid
Why in news?
Scientists have discovered that certain Antarctic microbes use an unusual genetic code to produce rare amino acids like pyrrolysine and selenocysteine, challenging long-held rules of biology and opening new possibilities in biotechnology. This adaptation helps them survive extreme cold and high UV radiation.​
About the discovery
- Genetic Code Shift: In most organisms, stop codons (signals to end protein synthesis) halt translation. But in these Antarctic microbes, one stop codon instead encodes a rare amino acid.
- Rare Amino Acids:
- Pyrrolysine – sometimes called the “22nd amino acid,” found in certain archaea.
- Selenocysteine – another rare amino acid, incorporated in humans but unusual in microbes.
- Microbial Adaptation: These microbes thrive in extreme cold and high UV radiation, and their altered genetic code may give them unique biochemical resilience.
Importance
- Breaks Biology’s Golden Rule: Traditionally, each codon corresponds to one amino acid or a stop signal. These microbes overturn that strict rule, showing genetic flexibility.
- Biotech Potential:
- Could allow scientists to engineer proteins with new functions.
- May lead to novel biomaterials or enzymes that perform better in extreme conditions.
- Evolutionary Insight: Demonstrates how life adapts to harsh environments, expanding our understanding of genetic diversity.
Challenges & Risks
- Protein Misfolding: Altered codes could cause instability if applied outside their native environment.
- Bioengineering Complexity: Incorporating rare amino acids into synthetic biology requires precise control.
- Ethical Concerns: Manipulating microbial genetics raises questions about unintended ecological impacts.
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