{"id":3522,"date":"2019-05-16T17:41:14","date_gmt":"2019-05-16T08:41:14","guid":{"rendered":"http:\/\/163.180.4.222\/lab\/?p=3522"},"modified":"2019-05-17T14:25:35","modified_gmt":"2019-05-17T05:25:35","slug":"total-synthesis-of-escherichia-coli-with-a-recoded-genome","status":"publish","type":"post","link":"https:\/\/biochemistry.khu.ac.kr\/lab\/?p=3522","title":{"rendered":"Total synthesis of Escherichia coli with a recoded genome & Scientists Created Bacteria With a Synthetic Genome. Is This Artificial Life?"},"content":{"rendered":"

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Abstract<\/strong><\/p>\n

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Nature uses 64 codons to encode the synthesis of proteins from the genome, and chooses 1 sense codon\u2014out of up to 6 synonyms\u2014to encode each amino acid. Synonymous codon choice has diverse and important roles, and many synonymous substitutions are detrimental. Here we demonstrate that the number of codons used to encode the canonical amino acids can be reduced, through the genome-wide substitution of target codons by defined synonyms. We create a variant of\u00a0Escherichia coli<\/i>\u00a0with a four-megabase synthetic genome through a high-fidelity convergent total synthesis. Our synthetic genome implements a defined recoding and refactoring scheme\u2014with simple corrections at just seven positions\u2014to replace every known occurrence of two sense codons and a stop codon in the genome. Thus, we recode 18,214 codons to create an organism with a 61-codon genome; this organism uses 59 codons to encode the 20 amino acids, and enables the deletion of a previously essential transfer RNA.<\/p>\n<\/div>\n

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(\uc6d0\ubb38: \uc5ec\uae30<\/a>\ub97c \ud074\ub9ad\ud558\uc138\uc694~)<\/p>\n

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Construction of an\u00a0Escherichia coli<\/i>\u00a0genome with fewer codons sets records<\/h4>\n

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The biggest synthetic genome so far has been made, with a smaller set of amino-acid-encoding codons than usual \u2014 raising the prospect of encoding proteins that contain unnatural amino-acid residues.<\/h5>\n
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Over the past decade, decreases in the costs of chemically synthesizing DNA and improved methods for assembling DNA fragments have enabled researchers to scale up synthetic biology to the level of generating entire chromosomes and genomes. So far, synthetic DNA has been constructed with up to one million base pairs, notably a set of chromosomes from the yeast\u00a0Saccharomyces cerevisiae<\/i>\u00a0and several versions of the genome of the bacterium\u00a0Mycoplasma mycoides<\/i>1<\/a><\/sup>,<\/sup>2<\/a><\/sup>. Now,\u00a0writing in\u00a0Nature<\/i><\/a>, Fredens\u00a0et al.<\/i>3<\/a><\/sup>\u00a0report the completion of a 4-million-base-pair synthetic version of the\u00a0Escherichia coli<\/i>\u00a0genome. This is a landmark in the emerging field of synthetic genomics, and finally applies the technology to the laboratory\u2019s workhorse bacterium.<\/p>\n

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