Magazine article Science News

Making Molecules That Copy Themselves

Magazine article Science News

Making Molecules That Copy Themselves

Article excerpt

Making molecules that copy themselves

Imagine building a machine whose physical structure provides instructions for its own construction and whose parts do double duty as the construction tools. Such a machine might even manage to make a copy of itself. Chemists at MIT have now assembled a rudimentary molecular machine of this sort, and they say it could serve as a model for probing the origins of the self-replicating biochemical systems inside cells.

"At best this can be regarded as a primitive sign of life," suggest Julius Rebek Jr. and his coauthors in the Jan. 31 JOURNAL OF THE AMERICAN CHEMICAL SOCIETY. At the very least, they say, their self-copying molecule should help scientists address a profound question of biochemistry: How did nucleic acids such as DNA and RNA come to embody a blueprint for making proteins -- the stuff of hair, muscles and key biological molecules such as enzymes?

The researchers assembled one of the system's two reactants, pentafluorophenyl ester, by covalently bonding it to one arm of a U-shaped molecular frame (Fig. 1 at right). With weaker hydrogen bonds, the second reactant -- called amino adenosine (Fig. 2) -- temporarily sticks to the frame's other arm. Amino adenosine closely resembles adenosine, a building block of nucleic acids. The specific patterns of hydrogen bonds that form between nucleic acid components endow the nucleic acids with their ability to carry and duplicate genetic information.

Thus positioned on the U-shaped frame, the reactants readily link to form an amide bond, the same kind of bond that links amino acids into proteins. …

Search by... Author
Show... All Results Primary Sources Peer-reviewed

Oops!

An unknown error has occurred. Please click the button below to reload the page. If the problem persists, please try again in a little while.