Depending on where these enzymes end up, they produce slightly different products.
"It looks like the old axiom of what's important in real estate -- location, location, location -- holds for some enzymes as well," says Brookhaven biochemist John Shanklin, author of a paper describing the first example of such location-dependent enzyme function in the July 13, 2004, issue of the Proceedings of the National Academy of Sciences.
Multifunctional enzymes such as these could substantially expand the diversity of metabolic products available to a cell, thereby increasing the organism's ability to adapt to changing conditions, Shanklin says. They may also offer scientists new ways to tailor plant products to meet specific needs, such as growing crop plants that make different, perhaps healthier oils.
Shanklin and his research associate Ingo Heilmann were studying a particular class of enzymes known as desaturases in Arabidopsis, the equivalent of the fruit fly for plant scientists. Desaturases remove hydrogen atoms from fatty acid chains to create carbon-carbon double bonds, desaturating the fat.
While using yeast cells to determine the functions of several newly discovered Arabidopsis desaturases, Heilmann and Shanklin noticed that one of the enzymes appeared to operate differently in yeast than it did in the plants: It inserted a double bond in a different place along the fatty acid carbon chain.
The scientists knew th
Contact: Karen McNulty Walsh
DOE/Brookhaven National Laboratory