JACS: breakthrough in artificial life! Scientists use artificial bacteria to synthesize unnatural proteins!

July 20, 2019 / BIOON / - synthetic biologists try to create new life with forms and functions that are not found in nature Although scientists still have a long way to go before they can create a completely artificial life form, they have created semi synthetic organisms with extended genetic codes that enable them to produce proteins that have never been seen before In a study recently published in JACS, researchers have optimized a semi synthetic bacterium that can effectively produce proteins containing unnatural amino acids Photo source: all natural life forms on JACS earth use a genetic code of four letters consisting of nucleotide deoxyadenosine (DA), deoxyguanosine (DG), deoxycytidine (DC) and deoxythymine (DT) to store information In DNA double helix, DA and DT are paired, and DG and DC form the "ladder" of DNA ladder Recently, researchers have created synthetic nucleotides that can bind to each other When they put these unnatural nucleotides into their genes, bacteria can replicate DNA, turn sequences into RNA, and then turn them into proteins with unconventional amino acids However, bacteria often can not use these synthetic sequences as effectively as natural sequences Therefore, Lingjun Li, Floyd romesberg and others hope to improve protein production by optimizing unnatural base pairs The researchers tested different unnatural base pair combinations in E.coli and observed which combinations had the highest replication efficiency and protein content Some synthetic base pairs have been tested, while others are new variants Then, using these optimized base pairs, the team demonstrated for the first time that a semi synthetic organism can produce a protein containing a variety of unnatural amino acids Reference: Aaron W Feldman et al, optimization of replication, transcription, and translation in a semi synthetic organization, Journal of the American Chemical Society (2019) Doi: 10.1021/jacs.9b02075