UW scientists report in the May 9 issue of the Proceedings of the National Academy of Sciences that Taq, a polymerase essential to genetic research, can be mutated up to 8,000 ways and still remain functional.
Taq is the polymerase most often used by geneticists to reproduce DNA for various research purposes. Previously, scientists believed that the active site of Taq was highly conserved and would not tolerate change. Premal Patel, a student in the lab of Lawrence Loeb, professor of biochemistry and pathology, inserted random DNA sequences into Taq and observed many different amino acids substituting for others without dramatically affecting the enzyme's overall function.
The research may illustrate how bacteria are able to become resistant to antibiotics or other treatment drugs through enzyme mutation. In addition, the 8,000 different active mutant forms discovered might be the largest library of any polymerase and any enzyme yet known.
Loeb is director of The Joseph Gottstein Memorial Cancer Research Laboratory and director of the UW's Medical Scientist Training Program. Patel is an M.D./Ph.D student in the Medical Scientist Training Program.