After finishing her doctorate degree at Jack Szostak’s lab in Harvard, Jennifer Doudna had been able to learn a lot about RNA and the opportunities that it presented. However, she soon realized that she would need to learn more about the structural biology of RNA if she wanted to truly understand the chemistry behind how ribozymes were able to self splice. In order to do this she would need to use X-ray crystallography, which was the same technology that Rosalind Franklin used to find the structure of DNA. Doudna also predicted that research into RNA could help lead to breakthroughs in other genetic technologies. So she decided to meet with Thomas Cech, who along with Sidney Altman had won the Nobel Prize for discovering ribozymes or self splicing RNA. Before leaving Harvard she visited Thomas at his office in the University of Boulder during a cross-country trip and discussed how her PhD thesis used some of his work. This conversation led Doudna to go to the University of Boulder in 1991 for her postdoctoral work where she would try to determine the structure of ribozymes. It was a difficult undertaking as RNA was not being explored much at the time due to how much scientific focus was being put on the human genome project. Moreover, images of RNA molecules had never been captured using x-ray crystallography beyond some simple structures in the 1970s. The lack of precedent in the area made it hard, but Doudna was able to partner up with a graduate student named Jamie Cate who had been using x-ray crystallography to study protein structure. Eventually they had a breakthrough when a technician accidentally placed a sample into a malfunctioning incubator, but when they took the sample out and looked at it under a microscope they found that it had formed a crystalline structure. However, their troubles weren’t over yet. The next hurdle they faced was that the crystals would break down when exposed to x-rays. Luckily, a biochemist from Yale named Tom Steitz was visiting Boulder at the time and his lab had been working on techniques to aid with crystallography. Specifically they were putting the crystals into liquid nitrogen to freeze them, so that the structure could be preserved even when exposed to x-rays. He helped arrange a flight for Doudna to visit Yale and test the new technique that his researches were using. When she got there it worked perfectly. As a result, Doudna accepted a job at Yale as a professor in 1993. Jamie Cate also came with her as a transfer graduate student. Cate was crucial in helping to overcome the last major obstacle they faced which was a problem with x-ray detectors only measuring certain parts of the wave. There were solutions to this problem for other molecules, but since RNA was not typically used in this process they had to find new methods. Cate was able to solve the problem by inserting a molecule called osmium hexamine into the crystal structure. After finalizing their method, they were able to finally get the electron-density maps they needed in order to formulate accurate depictions of the structure of RNA. After two years, Doudna and Cate were able to develop a finalized image of what the ribozyme molecules looked like, which allowed them to analyze how it was able to perform it’s specific functions. Unfortunately, this discovery coincided with the passing of her father, Martin, due to a brain tumor. Doudna would later go on to say “It was only after he died that I realized how influential he was in my decision to become a scientist…. I think my father would have loved to understand CRISPR. He was a humanist, a humanities professor, who also loved science. When I talk about CRISPR’s effects on our society, I can hear my father’s voice in my head.” Doudna was interviewed by a few news outlets after making her discovery. In two televised interviews she discussed how her discovery of the shape of RNA molecules could help contribute to better understanding of how RNA molecules perform their functions, which could then be used to help people with genetic disorders. Compilation of a some old television news segments about Jennifer Doudna's RNA structure discoveries Sources:
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AuthorMy name is Nathan Eberhart. I have a curious mind and am a creative thinker with an interest in biomedical engineering and medical devices. Archives
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