In the mid-1970s, as a physician who had come to the U.S. to study and wanting to learn more about DNA repair, Aziz Sancar reached out to one of the field’s pioneers, Dr. Claud Stanley Rupert at UT Dallas.
"I knew I watned to work on DNA repair, and I wanted to work with Dr. Rupert, so I contacted him," Sancar said. "He gave me an ambigious answer, so I just showeed up at his lab and said, 'You didn't say no.'"
At UT Dallas, Aziz's work focused on DNA repair in a bacterium, partly because in the 1970s, bacteria provided a much simpler experimental system than other organisms.
"UT Dallas was the world center for DNA repair research," Aziz said, "with at least five scientists working on different aspects. It was extremely stimulating intellectual environment."
As Sancar’s PhD advisor and mentor, Rupert suggested that he try to clone a gene for an enzyme called photolyase, which Rupert had been "playing" with, as the elder scientist described it. The enzume repairs a cell’s DNA that has been damaged by ultraviolet light.
"He worked tremendous hours," Rupert said. "He probably worked 90 hours a week. Nothing else existed but his work. If he wasn't in the lab, he was in the library reading journals."
Sancar successfully cloned that gene, and was the first to purify and describe photolyase.
“It was the foundation of everything I have done since,” he said.
Sancar elevated everybody’s game in the lab, said Rupert, now a UT Dallas professor emeritus.
“I never had a student like him. He’s my masterpiece, so to speak, except I didn’t do (the work), he did it. He’s the guy who put in the hours and just would not stop until he had it just the way he wanted it. It was a great experience to have him in the lab.