March 9, 2009
Scientists Move One Step Closer To Creating Artificial Life
Harvard University researchers said they have taken an important step toward making an artificial life form by creating a ribosome, known as the cell's factory, Reuters reported.
The proteins that carry out key business for all forms of life are created by the ribosome. Messenger RNA carries DNA's genetic instructions to a cell's ribosome, which then cooks up the desired protein.
All living organism from bacteria to humans uses a ribosome, and scientists say they are all strikingly similar.
George Church, a professor of genetics at Harvard Medical School, who directed the research with a single graduate student, said it is not quite artificial life, but an important step in that direction.
"If you're going to make synthetic life that is anything like current life ... you have got to have this ... biological machine," Church said. He acknowledged it could also have important industrial uses, especially for manufacturing drugs and proteins not found in nature.
Church said his group was not trying to make life in a test tube, but instead make designer proteins in lab dishes.
Church and post-doctoral fellow Mike Jewett have already synthesized firefly luciferase, the protein that makes them glow.
Most life forms have a quality called "chirality," meaning they are ultimately "right-handed" or "left-handed," but Church said his team was interested in creating a whole new kind of cell that is a mirror image of a replicating system.
However, chirality changes have been known to change the effects of drugs in the body, like in the case of thalidomide, which was once used to prevent morning sickness, but resulted in severe birth defects for some. It has left- and right-handed versions and only the "left" version caused the defects. However, the marketed drug contained both types.
Church said it might be possible to make other proteins in a lab dish without using living cells, which could include drugs that have been too hard to make now using a process called rational drug design, in which drugs are built molecule by molecule to have a specific mechanism of action.
Church stated that viruses, by most definitions, do not count as living organisms. He and other experts calculate that to build the simplest form of artificial but true life, it would take 151 genes.
Church said that 151 genes would be enough to replicate DNA, produce RNA, produce ribosomes and have a very primitive membrane.
Genome pioneer Craig Venter and a company called Synthetic Genomics Inc. are trying to create artificial life. Additionally, they are working on projects including synthetic vegetable oil that could be used as clean-burning biofuel.
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