Hamilton O. Smith Biography
Birthday: August 23, 1931 (Virgo)
Born In: New York City, New York
Hamilton Othanel Smith is a microbiologist from America who received the Nobel Prize for Physiology or Medicine in 1978. He shared the prize with two other microbiologists for the discovery of ‘restriction enzymes’ that could divide the DNA in a cell into smaller pieces so that its construction could be studied more easily. The other two microbiologists who shared the prize with him were Werner Arber from Switzerland and Daniel Nathans from America. The ‘restriction enzymes’ discovered by Smith was a new type of enzyme that could recognize a certain sequence of nucleotides in a DNA or ‘deoxyribonucleic acid’ molecule and could cut the molecule at that very point. This discovery laid the foundation for using ‘restriction enzymes’ as a tool in genetics and microbiology for studying the DNA of different kinds of biological systems in later experiments. Arber and other microbiologists had already found that one type of ‘restriction enzymes’ recognizes DNA sequences and cuts them up at random points but not at the point of recognition. Smith and his colleagues discovered the second type of ‘restriction enzymes’ while studying the ‘Haemophilus influenzae’ bacteria that not only recognizes a specific point of the DNA molecule but also cuts it exactly at the same point.