—Simpler Than DNA “Bare-bones nucleic acid structure may provide insight into prebiotic past” BIOCHEMISTRY Chemists have stripped the nucleic acid down to its bare essentials and introduced the simplest DNA analog known (J. Am. Chem. Soc. 2005, 127, 4174). Such a simple nucleic acid structure may have been early Earth's predecessor of today's more complex DNA and RNA, says Eric Meggers, an assistant professor of chemistry at the University of Pennsylvania. In addition, a simple nucleic acid backbone can significantly streamline the synthesis of DNA analogs commonly used as building blocks for new materials. Glycol nucleic acid (GNA; shown, B = base)—the analog introduced by Meggers, postdoc Lilu Zhang, and collaborator Adam Peritz—has just three carbon atoms and one stereocenter in the backbone, as opposed to five carbon atoms and four stereocenters in RNA's backbone. Nucleic acid researchers have thought that a cyclic sugar must be present in a nucleic acid phosphodiester backbone to give it the conformational preorganization it needs to base-pair and form a stable duplex with an opposite strand, Meggers says. They now know that that's not true, he adds, because GNA has no cyclic sugar and still displays Watson-Crick base pairing.
by LOUISA DALTON |
March 21, 2005