Rewriting the language of life

E. Coli bacteria

The familiar, idyllic scenery outside your door, bucolic in the spring sunshine, is exceedingly weird. And so are you.

What seems ordinary to us, an oak tree, daffodil, blade of grass, or your own body, is made of atoms forged in the furnace of early, distant stars. And these atoms are nearly entirely empty space, vacuum, with only a few protons and neutrons and electrons forming actual matter.

That’s right, your body is more than 99.9999% empty space, and the reason you don’t sink through your chair is that the electrostatic charge of the atoms in the chair repels the atoms of your body.

What’s the point? Only that things are often stranger than they seem.

Take living things, for instance. DNA is often called the blueprint of life. Think of DNA as a construction and operation manual that tells a dandelion how to be a dandelion, a whale a whale, or a you to be human. The instructions in your DNA account for your height, hair color, gender and also control the ongoing operation of your body. This is the miracle of life.

So it was a bit of a surprise earlier this month when synthetic biologists at the Scripps Research Institute announced  they had created bacteria containing artificial DNA. A biochemist not involved in the project, Steven Benner of the Foundation for Applied Molecular Evolution in Gainesville, Florida,  summed up the shocking finding: “Most people thought this wasn’t possible.”

Think of DNA as a kind of computer program. It is information that regulates how amino acids and proteins, the basis of life, are produced. The researchers at Scripps, led by chemical biologist Floyd Romesberg, have found a way to rewrite that program and have created bacteria which live, grow, and reproduce utilizing segments of man-made, artificial DNA. The descendant bacteria also contain the artificial DNA, and pass it on to their successors.

The point of all this is that bacteria can now be programmed to produce a greatly expanded range of amino acids and proteins. Applications range from new cancer drugs to improved vaccines or even anticounterfeiting, improved forensics, and the efficient production of biofuels. The opportunities are mind boggling.

Even before the achievement of artificial DNA, scientists had become quite capable. According to the Wall Street Journal, “With growing mastery, scientists have been tinkering with this natural information-storage system that is found inside every cell. They routinely cut and splice normal DNA to alter plants, bacteria and animals. They have used its ultraminiature storage capacity to encode books, poems and popular music. They even have programmed DNA to perform computer-like calculations.” (Man-Made DNA Opens Doors, 5/8/2014).

But the Scripps accomplishment opens the door to much greater control and specificity. While current gene manipulation relies on repurposing natural DNA, the advent of artificial DNA greatly expands the designer’s pallet. The natural e. coli bacteria used in this experiment can produce 20 amino acids. When augmented with the Scripps artificial DNA, they can create 172 amino acids. Since proteins are built from amino acids, the scope of protein creation is greatly extended.

There are safety concerns. A number of environmental groups had asked that this research be shut down until the safety aspects could be more fully assessed. But a review by the U.S. Presidential Commission for the Study of Bioethical Issues found no reason to call a halt. Their reasoning was that while the technique added some elements to the language of life, it did not fundamentally change the life process. The Scripps researchers did, however, add a safety feature. Their bacteria were designed to grow only in the presence of a specific chemical additive. In the absence of this additive, the bacteria would stop creating artificial DNA, thereby making escape to the wild highly unlikely.

In the end, whenever we think we have a handle on science, it surprises us. This achievement promises great advances in medical science and many other areas. Perhaps even the holy grail, that being the efficient conversion of carbon dioxide directly into biofuel. What a wonderful outcome, should it come to pass.