The ribosome is the biological molecular machine that adds amino acids to the end of a growing protein chain in the sequence specified by a molecular instruction tape—the messenger RNA molecule. The relevance of the ribosome to nanotech may be greatly increased by the announcement that synthetic ribosomes have been created and used to synthesize a complex protein named firefly luciferase. In an unusual departure from current scientific protocol, the research was announced at a university alumni association event prior to publication in a journal, so the details of exactly what has been done are not yet available. However, it would appear that the ability to assemble synthetic ribosomes opens the way to make proteins and protein-like polymers that cannot be made by natural ribosomes. Such polymers might be useful in biomimetic pathways to advanced nanotechnology. From Harvard University, written by Alvin Powell, Harvard News Office, “Taking a stride toward synthetic life“:
Harvard scientists have cleared a key hurdle in the creation of synthetic life, assembling a cell’s critical protein-making machinery in an advance with both practical, industrial applications and that advances the basic understanding of life’s workings.
George Church, a genetics professor at Harvard Medical School and member of Harvard’s Origins of Life Initiative, reported the creation of billions of synthetic ribosomes that readily create a long, complex protein called firefly luciferase.
Church, speaking at a Harvard Alumni Association and Origins of Life Initiative event at the Science Center on Saturday afternoon (March 7), described the advance for the first time publicly as part of an afternoon symposium called “The Future of Life.”
“We have not made artificial life, and that is not our primary goal, but this is a huge milestone in that direction,” Church said in comments on the work before the event.
Ribosomes are bodies inside of each cell that take the instructions from DNA and use them to create the proteins encoded by specific genes. Proteins are critical to forming the body’s structure, including muscles, bones and tendons, and are also critical in its daily functioning, through enzymes, for example, which control metabolism.
“The reason it is a step toward artificial life is that the key component of all living systems is the ribosome, which does protein synthesis. It is the most conserved and one of the most complicated biological machines,” Church said.
Using the bacteria E. coli, Church and Research Fellow Michael Jewett extracted the bacteria’s natural ribosomes, broke them down into their constituent parts, removed the key ribosomal RNA and then synthesized the ribosomal RNA anew from molecules.
Though the advance may create excitement among researchers interested in life’s basic functioning, Church said that the work’s industrial applications were its driving force.
Industry today manufactures proteins on a large scale using natural ribosomes, which evolved over millions of years for natural, not industrial, reasons. Church said that being able to create a ribosome means also being able to tweak it so it better fits industrial needs. One possible use would be to create mirror-image proteins that would be less susceptible to breakdown by enzymes, making them longer-lived.
“You really are in control. It’s like the hood is off and you can tinker directly,” Church said.
Additional comments on this work by other scientists can be found in coverage by Bloomberg.com and The Boston Globe. (Credit: ScienceDaily)
—Jim
