How bodies and plants repair UV damaged DNA | Science Blog:
For the first time, researchers have observed exactly how some cells are able to repair DNA damage caused by the sun's ultraviolet (UV) radiation.
The Ohio State University study revealed how the enzyme photolyase uses energy from visible light to repair UV damage.
This enzyme is missing in all mammals, including humans, although all plants and all other animals have it. Greater understanding of how photolyase works could one day lead to drugs that help repair UV damage in human DNA.
Scientists believe that all placental mammals lost the ability to make this enzyme some 170 million years ago, said Zhong, an assistant professor of physics and adjunct assistant professor of chemistry and biochemistry at Ohio State.
That's why humans, mice, and all other mammals are particularly vulnerable to cancer-causing UV rays from the sun. But the rest of the animal kingdom – insects, fish, birds, amphibians, marsupials, and even bacteria, viruses and yeast – retained a greater ability to repair such damage.