DNA Repair has been Captured in a step-by-step Molecular Movie

Unraveling the Secrets of DNA Repair: How Light Powers the Process

Have you ever wondered how our DNA repairs itself? Well, two teams of researchers have recently made groundbreaking discoveries about a protein called photolyase and its ability to use light to repair DNA. This newfound knowledge not only sheds light on the intricate mechanisms of DNA repair but also holds promise for the development of sustainable technologies that harness sunlight for chemical manufacturing.

The Marvel of Photolyase

Photolyase is a protein found in most organisms, except for many mammals. Its primary function is to repair DNA damage caused by UV radiation using light. According to Thomas Lane at the German Electron Synchrotron (DESY), photolyase is incredibly efficient at utilizing every photon it captures. In other words, it can generate a DNA repair for every single photon of light it receives.

So, how does photolyase accomplish this remarkable feat? To understand the process, we need to delve into the structure of DNA itself.

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The Dance of DNA

DNA is composed of two molecular strands that intertwine, resembling a spiral staircase. Each strand consists of chemical bases that connect with their counterparts on the opposite strand, holding the structure together. When DNA is damaged, these base pairs can break apart, causing adjacent bases on the same strand to bond together instead.

Previous research has shown that photolyase isolates the damaged area and separates the unwanted bonds between adjacent bases, allowing them to reconnect with their counterparts on the opposite strand. However, the exact mechanism behind this process has remained a mystery.

Unveiling the Repair Process

Researchers, led by Thomas Lane and Manuel Maestre-Reyna, employed innovative techniques to capture the repair process in atomic detail. Using pulses of high-energy X-rays, they created a stop-motion animation of the repair process, revealing the intricate steps involved.

During the experiments, the researchers initiated the repair process by shining a laser on photolyase in the presence of damaged DNA strands. They then used rapid X-ray pulses to capture a sequence of images, providing insights into the arrangement of atoms during the repair process, which lasts approximately 200,000 nanoseconds.

The Dance Steps of Photolyase

The researchers discovered that the region of photolyase responsible for initiating DNA repair, known as the cofactor, initially forms a V shape. When it absorbs light, it enters a highly energetic state, flipping upside down into an inverted V shape. The rest of the protein stabilizes the excited cofactor while it transfers an electron to the damaged DNA. This electron breaks the bonds between the adjacent DNA bases one by one. Subsequently, the electron returns to the cofactor, which resumes its upward V shape. Once the bonds are broken, the photolyase releases one base at a time, allowing them to rejoin their counterparts on the opposite strand.

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These groundbreaking findings provide unprecedented insights into the structure and function of photolyase. Marten Vos at École Polytechnique in France emphasizes that such detailed knowledge of photolyase’s operation could pave the way for the development of energy-efficient proteins that enable sustainable chemical manufacturing.

Unlocking the Potential of Light-Powered DNA Repair

The discoveries made by these research teams not only unravel the mysteries of DNA repair but also hold immense potential for the development of light-based manufacturing technologies. By understanding how photolyase efficiently utilizes light to repair DNA, scientists can explore ways to harness similar energy-efficient processes for manufacturing chemicals and products more sustainably.

Photo: Freepik.com

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