"It's amazing that although these bases look totally foreign, as long as they fit together properly, like two jigsaw puzzle pieces, enzymes perceive them as part of a DNA molecule and copy them accordingly. Not only do you not need hydrogen bonds to copy DNA, you don't even need the traditional shape of the individual bases," says Kool.
One possible application of the current work, Kool says, is a test for cancer-causing agents that cause mutations by knocking out a single base, which is the most common form of mutation in our bodies. The double-size molecule the team developed is such an effective molecular impostor that polymerase enzymes insert it into any "abasic" site, where a single base is missing, kind of like a party guest who is always looking for an empty chair. The molecule, a pyrene nucleoside triphosphate, fluoresces brightly, flagging mutations and sending an easily visible signal whenever a base is missing.
Kool's vein of research on novel types of DNA and RNA has been adopted
by several other laboratories and has a variety of other applications. He has
developed "rolling circles" of DNA, providing an inexpensive way to produce
hundreds of copies of an RNA molecule by spinning them off like a mimeograph
machine. The laboratory has developed loops of DNA and RNA that form a triple
helix with single strands, enveloping them like a bun around a hot dog and
knocking them out. The
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Contact: Tom Rickey
trickey@admin.rochester.edu
716-275-7954
University of Rochester
16-Jun-1999