It might seem incredible that a bright young student should reject admission to the Indian Institute of Technology (IIT) to study basic science, but Anirban Banerjee did exactly that. And his venture seems to have paid off, for this year he became the first Indian to win the Nobel Laureate Signature Award of the American Chemical Society.
Banerjee works in the field of DNA repair and his efforts have provided “detailed new insights into how proteins search for damage”. The award carries a sum of $3,000 and a plaque signed by resident Nobel laureates in chemistry in the US, and bears the ratification of the Alfred Nobel Society.
Banerjee’s mentor at Harvard University, Gregory L. Verdine, is ecstatic. “Anirban’s work contributed significantly to the renewal of funding from the National Institutes of Health for a cornerstone project in my laboratory,” he says. A postdoctoral research fellow at Rockefeller University, Banerjee says that the basis of his work that won him the laurel was to understand the chemical details of one of the DNA repair pathways called the base excision system.
“DNA contains all the programmes needed to maintain a living cell but at the chemical level, it is nothing but a chemical polymer,” expounds Banerjee. And like all other chemical substances, it is prone to modifications. These modifications — caused by external agents such as toxic pollutants and ultraviolet light as well as reactive byproducts of a host of cell processes — take place constantly and are collectively called DNA damage.
“Since DNA contains essential genetic information, these changes threaten the integrity of the very information it carries,” he elaborates. Hence, damaged DNA must be restored to its undisturbed form. There are pathways in all living organisms for doing so and these are collectively known as DNA repair pathways. Repair enzymes locate and excise damaged DNA nucleobases embedded in a huge pool of undamaged DNA, “and this represents one of the most formidable needle-in-a-haystack challenges in biology,” says Banerjee.
Verdine challenged Banerjee to formulate a strategy for using a chemical cross-link to catch these enzymes in the act of searching the haystack, and the latter seemed only too eager. “At the time, most people in my lab thought it could not be done,” recollects Verdine, but Banerjee was not to be discouraged. He eventually developed a powerful cross-linking system that made it possible to crystallise otherwise uncrystallisable complexes of DNA repair proteins bound to short stretches of DNA. Till then, Verdine’s laboratory had been unsuccessful in crystallising the bacterial enzyme charged with prevention of dangerous DNA mutations. But Banerjee’s cross-linking strategy shows how this enzyme recognises a mistaken pairing of DNA bases.
| Anirban Banerjee has unravelled the chemical details of a DNA repair pathway called the base excision system
Born in 1974, Banerjee attributes his intellectual development to the childhood influences of his father, Amalendu Bandopadhyay, a former director of the Positional Astronomy Center in Calcutta. “During the Eighties, when Calcutta would be submerged in darkness because of frequent power cuts, he would be out on the terrace showing me the different stars, planets and constellations,” recalls Banerjee.
Banerjee was selected for admission to IIT Kanpur for Integrated MSc programme in chemistry. But finding this to be an unsatisfactory prospect, he left and joined the BSc (Honours) programme in chemistry at Jadavpur University, Calcutta. “I had some truly outstanding teachers at Jadavpur and have never regretted that decision,” he says.
After a two-year stint for an MSc at IIT Kanpur and some time at Professor Goverdhan Mehta’s laboratory in Central University in Hyderabad, Banerjee left for the US. “I wanted to do research in chemical biology which meant using the tools and concepts of chemistry to understand biological problems at a molecular level. And Harvard seemed to be the ideal place for this,” he points out.
Banerjee feels that advancement in basic science is extremely significant since it frequently finds application in technology or medicine many years after the original research has been concluded. “Curiosity driven research is thus important,” he says.
Banerjee is optimistic about India’s growing contribution to science and technology and feels the media has a great role to play in bringing forward complicated scientific ideas to the mainstream of public consciousness. “Local talent needs to be tapped and therein lies the secret of scientific progress,” he says.