Nobel laureate Hamilton Smith, who discovered the molecular 'scissors' to cut DNA, has passed away at the age of 94. His groundbreaking work in genetic engineering has left an indelible mark on the scientific community. Smith, a microbiologist, made a pivotal discovery in 1978 that earned him the Nobel Prize in Medicine. This discovery involved restriction enzymes, which are molecular tools that can precisely cut DNA, revolutionizing the field of genetic engineering. The enzymes, known as 'scissors,' have paved the way for significant advancements in biotechnology, including genome sequencing and genetic recombination. Smith's work, alongside his colleagues Daniel Nathans and Werner Arber, laid the foundation for modern genetic research. Nathans, a fellow professor at Johns Hopkins University School of Medicine, praised Smith's adventurous spirit in science. Smith's journey began at Johns Hopkins, where he graduated from medical school in 1956 and later became a professor emeritus. His early research focused on genetic recombination, particularly in the bacterium Haemophilus influenzae, which has implications for respiratory illnesses. A pivotal moment came when Smith and his graduate student, Kent Wilcox, discovered an enzyme that could cut viral DNA but not bacterial DNA, a finding that led to the identification of the Hind II enzyme. This enzyme, named after its ability to cut DNA at specific sequences, has been instrumental in various applications, from inserting the insulin gene into bacteria to diagnosing genetic diseases. Over the years, thousands of restriction enzymes have been discovered, contributing to advancements in DNA analysis and genetic research. Smith's later collaborations with J. Craig Venter's group at the Institute for Genomic Research led to significant breakthroughs in genome sequencing. After his retirement from Johns Hopkins, Smith continued to contribute to the field of synthetic biology, playing a crucial role in the design and construction of a minimal synthetic bacterial cell. In recognition of his achievements, the Johns Hopkins University School of Medicine established the Hamilton Smith Award for Innovative Research in 2015, honoring his legacy in the field of genetic engineering.
