Restriction enzymes are specific proteins which cut DNA at specific positions within the DNA sequence.
Specific blocks of 3,4, 5, or 6 bases are snipped by a unique restriction enzyme. These molecular scissors made genetic engineering possible and constitute one of the pillars of modern biotechnology.
The molecular scissors are made by bacteria as a natural defense against foreign DNA. The goal of this project was to discover novel restriction enzymes from Ugandan soil samples. Soil samples from various locations in Uganda were suspended in water, the suspension was streaked onto plates, and the plates put in an incubator for 24 hours. Bacterial colonies were picked, grown up in large volumes and the bacteria broken up by ultrasound (sonication). Restriction enzyme activity in bacterial extracts was identified using known DNA substrates. Thousands of restriction enzymes were identified; one enzyme from an isolate from a field in Western Uganda was novel. Its activity suggests that it is an isoschizomer of xxxxx and was designated BspU1.