Screen of 250,000 Species Reveals Tweaks to Genetic Code

A massive screen of bacterial and archaeal genomes revealed five previously unknown instances where an organism uses an alternate code to translate genetic blueprints into proteins.

Written byDan Robitzski

| 5 min read

Artist’s rendering of the protein synthesis process, in which a tRNA molecules carry amino acids to a ribosome that’s decoding a strand of mRNA.

Transfer RNA (tRNA) molecules ferry amino acids to a ribosome as it decodes a strand of mRNA to make a protein.

Image credit:© ISTOCK.COM, SELVANEGRA

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The genetic code that dictates how genetic information is translated into specific proteins is less rigid than scientists have long assumed, according to research published today (November 9) in eLife. In the paper, scientists report screening the genomes of more than 250,000 species of bacteria and archaea and finding five organisms that rely on an alternate genetic code, signifying branches in evolutionary history that haven’t been fully explained.

The genetic code refers to how sequences of DNA nucleotide bases lead to specific chains of amino acids during the process of protein synthesis. To perform this synthesis, ribosomes read strands of mRNA—copies of bits of the organism’s genome—in chunks of three bases at a time. Each three-base sequence, known as a codon, binds to a specific transfer RNA (tRNA) that ferries a corresponding amino acid to the ribosome to the added to the protein chain. An organism with an alternate genetic ...

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Meet the Author

Dan Robitzski
Dan is an award-winning journalist based in Los Angeles who joined The Scientist as a reporter and editor in 2021. Ironically, Dan’s undergraduate degree and brief career in neuroscience inspired him to write about research rather than conduct it, culminating in him earning a master’s degree in science journalism from New York University in 2017. In 2018, an Undark feature Dan and colleagues began at NYU on a questionable drug approval decision at the FDA won first place in the student category of the Association of Health Care Journalists' Awards for Excellence in Health Care Journalism. Now, Dan writes and edits stories on all aspects of the life sciences for the online news desk, and he oversees the “The Literature” and “Modus Operandi” sections of the monthly TS Digest and quarterly print magazine. Read more of his work at danrobitzski.com.
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