Figure 1.

Demonstration of ATase activity in archaeal cell extracts. The standard ATase assay was performed at the optimal growth temperatures of the individual strains; •, S. acidocaldarius (78°C); ▴, P. islandicum (100°C); ▾, Pyrococcus furiosus (100°C); ▪, T. litoralis (88°C); ○, E. coli BS21 (37°C); □, E. coli overexpressing human ATase (37°C). Cell extracts were incubated at these temperatures with ³H-labeled substrate DNA for 20 min (S. acidocaldarius, T. litoralis), 10 min (P. islandicum, Pyrococcus furiosus) or 60 min (BS21, human). See text for details.