Which biochemist discovered the first restriction enzyme, HindII, in 1970?

Hamilton Smith discovered the first restriction enzyme, HindII, in 1970.

Restriction enzymes are proteins that cut DNA at particular sequences. Smith identified HindII while studying the bacterium Haemophilus influenzae. The enzyme recognizes a specific DNA sequence and cuts within it, providing researchers with a precise molecular tool for examining and recombining genetic material.

This discovery helped launch modern recombinant DNA technology. Restriction enzymes made it possible to cut DNA from different sources and join selected fragments, a foundation for gene cloning, DNA mapping and many laboratory techniques used today.

Smith shared the 1978 Nobel Prize in Physiology or Medicine with Werner Arber and Daniel Nathans. Arber had proposed the restriction-modification system, while Nathans demonstrated how restriction enzymes could be used to map DNA. The enzyme is named after its bacterial source: Haemophilus influenzae strain d, abbreviated Hind.