A revolutionary milestone in synthetic biology, scientists have successfully designed a bacterium with ribosomes made from proteins that utilize only 19 amino acids, rather than the standard 20 seen in all life forms on Earth. This pioneering effort involved rewriting the genetic code of Escherichia coli (E. coli), making a substantial contribution towards developing an organism that functions with a reduced number of amino acids. Such progress in synthetic biology offers exciting potential for the discipline, providing researchers with novel methods to investigate organism evolution with more streamlined genomes.<\/p>\n
While nature presents approximately 500 distinct amino acids, merely 20 are regularly used to form the proteins present in all living beings. Occasionally, certain organisms incorporate additional amino acids, reaching up to 21 or 22, but no natural organism has ever been recorded as functioning with fewer than 20. Notably, computer models suggest that just 9 to 12 amino acids could potentially encode the majority of protein structures, indicating that primitive organisms may have employed a more limited assortment of amino acids compared to contemporary organisms.<\/p>\n
The proteins synthesized within a cell’s ribosomes are built using 20 amino acids that are encoded by a ‘universal codon table’, which features 64 possible combinations of three DNA base pairs, referred to as codons. Many of these codons redundantly encode the same amino acid. In 2025, researchers in the U.K. engineered E. coli with a 57-codon genetic code that encodes all 20 amino acids, effectively reducing redundancy within the genetic code.<\/p>\n
This latest experiment went beyond earlier synonymous mutations by altering E. coli’s genome so that one amino acid was omitted from ribosomal proteins. By investigating various species, researchers found that isoleucine was often replaced by other amino acids, particularly valine. However, genetic modifications that substituted isoleucine with valine yielded mixed results; some bacterial colonies thrived, while others did not.<\/p>\n
Utilizing deep learning models for protein structure, researchers devised more intricate substitution strategies. Sergey Ovchinnikov from the Massachusetts Institute of Technology notes that protein models reflect the evolutionary relationships among amino acids. Through this advanced technique, the researchers succeeded in cultivating E. coli with ribosomal proteins missing isoleucine, while the rest of the cell’s proteins still contained it. The modified bacteria exhibited growth at about 60% the rate of typical E. coli. Harris Wang from Columbia University aims to eventually create an organism using solely a 19-amino-acid system.<\/p>\n
Chang Liu of the University of California, Irvine, views these discoveries as crucial, establishing a foundation and underscoring significant technical hurdles in progressing towards a 19-amino-acid bacterium. Such organisms might have a ‘genetic firewall’ against viruses that target hosts’ DNA. By eliminating the components required to incorporate isoleucine into the genetic code, cells could effectively neutralize viruses reliant on proteins that include isoleucine. Ultimately, this accomplishment enables comparative studies between organisms utilizing 19 and 20 amino acids, providing enhanced understanding into molecular biology and protein realms.<\/p>\n","protected":false},"excerpt":{"rendered":"
A revolutionary milestone in synthetic biology, scientists have successfully designed a bacterium with ribosomes made from proteins that utilize only 19 amino acids, rather than the standard 20 seen in all life forms on Earth. This pioneering effort involved rewriting the genetic code of Escherichia coli (E. coli), making a substantial contribution towards developing an […]<\/p>\n","protected":false},"author":2,"featured_media":372282,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"Default","format":"standard","meta":{"footnotes":""},"categories":[1],"tags":[174],"class_list":["post-372281","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-uncategorized","tag-source-chemistryworld-com"],"_links":{"self":[{"href":"https:\/\/wolfscientific.com\/index.php?rest_route=\/wp\/v2\/posts\/372281","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/wolfscientific.com\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/wolfscientific.com\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/wolfscientific.com\/index.php?rest_route=\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/wolfscientific.com\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=372281"}],"version-history":[{"count":0,"href":"https:\/\/wolfscientific.com\/index.php?rest_route=\/wp\/v2\/posts\/372281\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/wolfscientific.com\/index.php?rest_route=\/wp\/v2\/media\/372282"}],"wp:attachment":[{"href":"https:\/\/wolfscientific.com\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=372281"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/wolfscientific.com\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=372281"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/wolfscientific.com\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=372281"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}