Science Daily — Scientists have determined for the first time the atomic structure of an ancient protein, revealing in unprecedented detail how genes evolved their functions.
"Never before have we seen so clearly, so far back in time," said project leader Joe Thornton, an evolutionary biologist at the University of Oregon. "We were able to see the precise mechanisms by which evolution molded a tiny molecular machine at the atomic level, and to reconstruct the order of events by which history unfolded."
A detailed understanding of how proteins -- the workhorses of every cell -- have evolved has long eluded evolutionary biologists, in large part because ancient proteins have not been available for direct study. So Thornton and Jamie Bridgham, a postdoctoral scientist in his lab, used state-of-the-art computational and molecular techniques to re-create the ancient progenitors of an important human protein.
quote:Thornton and Jamie Bridgham, a postdoctoral scientist in his lab, used state-of-the-art computational and molecular techniques to re-create the ancient progenitors of an important human protein.
Thornton then collaborated with University of North Carolina biochemists Eric Ortlund and Matthew Redinbo, who used ultra-high energy X-rays from a stadium-sized Advanced Photon Source at Argonne National Laboratory near Chicago to chart the precise position of each of the 2,000 atoms in the ancient proteins. The groups then worked together to trace how changes in the protein's atomic architecture over millions of years caused it to evolve a crucial new function -- uniquely responding to the hormone that regulates stress.
So they synthesised an evolutionary precursor gene, based on molecular data, and then expressed it. Then they used X-ray crystallography to see the structure.
ABE: Just noticed this:
quote:...X-ray crystallography, a state-of-the art technique...
. Those among you who remember DNA was discovered to be a double-helix via x-ray crystallography may feel free to laugh.
Edited by Doddy, : abe
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