Purification, crystallization and preliminary X-ray crystallographic analysis of Pyrococcus furiosus DNA polymerase

DNA polymerase gene from the hyperthermophilic Archaeon Pyrococcus furiosus has been cloned and the protein overexpressed in Escherichia coli to produce an active enzyme. The purified protein was crystallized from 0.08 M ammonium sulfate, 0.05 M Na-cacodylate, pH 6.5, 0.15%(v/v) NP40, 0.05%(v/v) Tween 20 and 4.5% (w/v) polyethylene glycol 6000 by the vapour-diffusion method. The orthorhombic crystals had unit-cell dimensions of a = 92.5, b = 125.4, c = 192.1 Angstrom: alpha = beta = gamma = 90 degrees. The crystals diffracted beyond 4 Angstrom on a 1.08 Angstrom synchrotron radiation source.