The Nobel Prize in Chemistry for this year goes to 3 scientists: Tomas Lindahl from Sweden, Paul Modrich from the US, and Aziz Sancar from Turkey. Each of the trio discovered different mechanisms pertaining to natural DNA repair.
Natural DNA repair is crucial for life to be sustained. Knowledge of the mechanisms is specially important in our contemporary world where DNA is increasingly being damaged by external factors – such as exposure to UV light, smoking, radiation and carcinogens – on top of the natural mistakes that might occur during DNA replication. These mistakes have to be repaired right away to ensure that the DNA is copied correctly, thereby preserving essential information needed to support life.
Tomas Lindahl showed that mistakes and related problems are always happening such that life would not have developed if there were no repair mechanism. He discovered the mechanism called base-excision repair whereby incorrect bases are removed and replaced with the correct ones.
As for Paul Modrich, he observed the mechanism called DNA mismatch repair. With the assistance of his colleague Matthew Meselson, he found that mismatched DNA can be repaired through enzymes that tweak a piece of DNA that bears the incorrect base pairing.
Aziz Sancar discovered the nucleotide excision repair mechanism whereby enzyme exinuclease spots DNA damaged by UV light and removes the strand for it to be substituted with non-damaged bases by enzyme DNA polymerase.
The discoveries further enhance our understanding of the functioning of the human body at biochemical level. Furthermore, it is hoped that the new insight will help develop new treatment for diseases resulting in DNA damage, such as cancer. For instance, many anti-cancer drugs are known to damage DNA.
Find a summary of the mechanisms in the schema below:-
Image credits: http://bit.ly/NobelSci2015.