Figure 1.

Purification of wild-type Pnk and Pnk-Ala mutants. (A) Pnk purification. Aliquots (5 µg) of the indicated nickel–agarose Pnk preparations were analyzed by SDS–PAGE. Polypeptides were visualized by staining the gel with Coomassie brilliant blue dye. A scan of the stained gel is shown. The positions and sizes (in kDa) of marker proteins are indicated on the left. (B) The amino acid sequence of T4 Pnk from amino acids 2 to 288 is aligned with that of the related ORF86 polypeptide encoded by Autographa californica nuclear polyhedrosis virus (AcNPV). The amino acids of Pnk that were previously mutated to alanine are denoted by + (non-essential for activity) or • (important for either 5′-kinase or 3′-phosphatase activity). The amino acids in Pnk that were mutated to alanine in the present study are indicated by !.