Scientists in quest to unravel health secrets of the DNA twist

People suffering from genetic conditions such as cancer and premature aging could benefit from new research that seeks to explain how changes in the structure of DNA inside cells can cause disease.

Scientists will study the long strands of DNA, like rope, which contain instructions for human development and function. These strands are twisted into helical chains coiled round the same axis forming the famous double helix.

They want to know why individual DNA chains can become over or under twisted causing problems within cells.  ( IMAGE: DNA wrapped around protein - Proteins wrap around DNA to protect it from damage and regulate how it is read and copied by the cell machinery )

Researchers say that the main protein for reading the complete copy of DNA - known as the genome - also acts as a motor that twists it. Proteins also help protect DNA from damage and regulate how it is read by any cell.

When DNA becomes over or under twisted, a healthy cell counteracts this by cutting and resealing the DNA thereby releasing extra helical twists in each strand. 

Over twisting causes cells difficulty in performing routine molecular functions such as reading DNA to make proteins and copying DNA to make new genetic code.

The fragility caused by over twisting results in mutations or breaks in the genome making people susceptible to diseases like cancer and premature aging. This process is further accentuated in patients that already have other rare medical conditions, scientists say.

Professor Nick Gilbert of the Medical Research Council Institute of Genetics and Molecular Medicine at the University of Edinburgh explains: "In a healthy cell there is a perfect balance between the motors that introduce twist into the DNA strand and the molecular scissors that release it. This means that the shape of the DNA twist in cells is optimal. We are going to look at what drives the DNA to become over or under twisted and understand how cells know when to operate their molecular scissors to release the extra twist."

Scientists working on the project, which has received £2.7 million from the Medical Research Council, also hope to discover the health effects of under twisted DNA.

Please see Professor Gilbert's short video on Packaging the Genome:

http://homepages.inf.ed.ac.uk/srodnes/CSE/?p=3853

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