https://phys.org/news/2020-08-chemists-genetic-code-coli-21st.html
Rice University researchers introduced noncanonical amino acid building blocks into proteins in living cells, pioneering a powerful tool for investigating and manipulating the structure and function of proteins. The resulting unnatural organism, a strain of Escherichia coli bacteria, is able to monitor low levels of oxidative stress. Credit: Xiao Lab/Rice University
Rice University chemist Han Xiao and his team have successfully expanded the genetic code of Escherichia coli bacteria to produce a synthetic building block, a "noncanonical amino acid." The result is a living indicator for oxidative stress.
The work, they say, is a step toward technologies that will allow the generation of novel proteins and organisms with a variety of useful functions.
Their study appears in the Cell Press journal Chem.
Amino acids are the building blocks of DNA. In general, organisms need only 20 of them to program the entire set of proteins necessary for life. But Xiao, with the help of a $1.8 million National Institutes of Health grant, set out to see how a 21st amino acid would enable the design of "unnatural organisms" that serve specific purposes.
more at link............
the paper:
https://www.cell.com/chem/fulltext/...om/retrieve/pii/S2451929420303636?showall=tru
Creation of Bacterial Cells with 5-Hydroxytryptophan as a 21st Amino Acid Building Block
Summary
While most organisms utilize 20 canonical amino acid building blocks for protein synthesis, adding additional candidates to the amino acid repertoire can greatly facilitate the investigation and manipulation of protein structures and functions. In this study, we report the generation of completely autonomous organisms with a 21st noncanonical amino acid, 5-hydroxytryptophan (5HTP). Like 20 canonical amino acids, 5-hydroxytryptophan can be biosynthesized in vivo from simple carbon sources and is subsequently incorporated into proteins in response to the amber stop codon. Using this unnatural organism, we have prepared a single-chain immunoglobulin variable fragment conjugated with a fluorophore and demonstrated the utility of these autonomous cells to monitor oxidative stress. The creation of this and other cells containing the 21st amino acid will provide an opportunity to generate proteins and organisms with novel activities, as well as to determine the evolutionary consequences of using additional amino acid buildings.
Rice University researchers introduced noncanonical amino acid building blocks into proteins in living cells, pioneering a powerful tool for investigating and manipulating the structure and function of proteins. The resulting unnatural organism, a strain of Escherichia coli bacteria, is able to monitor low levels of oxidative stress. Credit: Xiao Lab/Rice University
Rice University chemist Han Xiao and his team have successfully expanded the genetic code of Escherichia coli bacteria to produce a synthetic building block, a "noncanonical amino acid." The result is a living indicator for oxidative stress.
The work, they say, is a step toward technologies that will allow the generation of novel proteins and organisms with a variety of useful functions.
Their study appears in the Cell Press journal Chem.
Amino acids are the building blocks of DNA. In general, organisms need only 20 of them to program the entire set of proteins necessary for life. But Xiao, with the help of a $1.8 million National Institutes of Health grant, set out to see how a 21st amino acid would enable the design of "unnatural organisms" that serve specific purposes.
more at link............
the paper:
https://www.cell.com/chem/fulltext/...om/retrieve/pii/S2451929420303636?showall=tru
Creation of Bacterial Cells with 5-Hydroxytryptophan as a 21st Amino Acid Building Block
Summary
While most organisms utilize 20 canonical amino acid building blocks for protein synthesis, adding additional candidates to the amino acid repertoire can greatly facilitate the investigation and manipulation of protein structures and functions. In this study, we report the generation of completely autonomous organisms with a 21st noncanonical amino acid, 5-hydroxytryptophan (5HTP). Like 20 canonical amino acids, 5-hydroxytryptophan can be biosynthesized in vivo from simple carbon sources and is subsequently incorporated into proteins in response to the amber stop codon. Using this unnatural organism, we have prepared a single-chain immunoglobulin variable fragment conjugated with a fluorophore and demonstrated the utility of these autonomous cells to monitor oxidative stress. The creation of this and other cells containing the 21st amino acid will provide an opportunity to generate proteins and organisms with novel activities, as well as to determine the evolutionary consequences of using additional amino acid buildings.
