One of America’s top scientists, biochemist Dr. Bruce Alberts, came to Alabama’s HudsonAlpha Institute for Biotechnology this week to talk about what’s wrong with modern science education. More on that in a later report.
But because he was at a Huntsville DNA research center that had just given him an award for his own contributions to genomic research, Alberts took 10 minutes to talk about his work in finding out how DNA works. He showed an amazing video (below) on DNA copying. What Alberts said won’t make us biochemists in 10 minutes, but it does help explain a subject that is more important in medicine every day.
Here’s what Alberts said in five bites:
1. Before James Watson and Frances Crick discovered the DNA double helix in 1953, heredity was “a mystery.” No one knew why we look like our parents and pass down features like a strong nose or weak chin for generations.
“It was incomprehensible how this information could be stored so stably and in such a small place (as a cell)…,” Alberts said. “All that information had to be stored in such a tiny space, and we know that anything small at a molecular level is going to be subject to thermal degradation of its environment – that’s just pure physics – so what a puzzle this was. How could you possibly do it?”
2. Watson and Crick’s “famous prediction, which was correct,” was that there are two strands of DNA, each carrying the same code, Alberts said. That’s how the information was protected.
But Watson and Crick “completely missed – partly because they’re not chemists – the crucial thing about having two strands,” he said. “Anybody who’s a computer scientist will recognize that everything degrades, even computer memory, so we always have multiple copies.” In the process of DNA copying, one strand copies and “the opposite strand leads a repair process” to fix any copying errors.
3. “In fact,” Alberts said, “human beings use at least 10 times as many genes to correct our DNA as to (copy) it. It’s really a central feature. And failure of DNA repair is very important in cancer. That’s how all these mutations accrue and eventually kill us, if we get a dangerous cancer cell.”
4. Alberts focused in his own research on how DNA copies itself or replicates. (He later wrote a famous textbook on the cell, became president of the National Academy of Sciences and editor-in-chief of Science magazine.)
“We discovered that life is based on what I call a protein machine,” Alberts said. “The chemistry of life is by far the most complicated and sophisticated of any chemistry in the universe – as far as we know – and nobody ever predicted that there would be machines that underlie how we work – tiny little miniature machines.”
The “machines” copy and repair the DNA strands whose proteins decide what each of our cells becomes: heart cells, brain cells, skin cells, etc.