Purification of the restriction endonuclease PalI.

The restriction endonuclease PalI was purified from Providencia alcalifaciens 1650-fold with a yield of 33%. The purified protein moved as a single band upon polyacrylamide gel electrophoresis. When this was carried out in the presence of sodium dodecyl sulfate, a molecular weight of 31,000 was obtained for PalI. Gel filtration through Sephacryl S200 gave molecular weights ranging from 44,000 to 53,000 when 58 to 1870 ng/ml enzyme were used, respectively. Other properties of the enzyme are described.