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Paired down

发布时间:2019-03-07 02:04:07来源:未知点击:

By Bob Holmes in San Francisco A POWERFUL new technique for finding out what newly sequenced genes do has been developed by researchers in California. The strategy involves using a computer to home in on pairs of genes that have become inseparable during evolution. Almost all of a cell’s daily business involves interactions between proteins such as enzymes, signalling molecules and structural components. So knowing what an unidentified protein interacts with can help biochemists to figure out exactly what it does. But there are millions of possible protein pairs to test individually. “Doing that by experimental means is just a vast project,” says David Eisenberg of the University of California in Los Angeles. To whittle down those possibilities to manageable numbers, Eisenberg and his colleagues sifted through complete genomes of organisms to find instances where two genes code for two separate proteins in one organism, but the same sequences are combined to form a single gene for a single protein in another. If evolution has seen fit to combine two components, they reason, the proteins probably interacted even when separate. The team looked for pairs of genes in the bacterium Escherichia coli that were combined into single genes in other organisms. Sure enough, the 6809 such pairs were more likely to share a common function than random pairs of proteins (Science, vol 285, p 751). A few pairs had already been experimentally proven to interact. Genome experts say Eisenberg’s new technique—along with another computer-based strategy he devised—provides a valuable shortcut by narrowing the possibilities that need to be tested. “What you do on a computer is easier than almost anything you can do in the lab, so anything you can get, you take,” says Roger Brent, a molecular biologist at the Molecular Sciences Institute in Berkeley,