FIG. 2.

ATPase and autophosphorylation activities of DnaK and DnaK derivatives free of NDP kinase activity. Eadie-Hofstee plots of ATPase activity for DnaK and DnaK derivatives purified by the extended protocol are shown. DnaK (final concentration, 7.24 nM) was incubated with [α-³²P]ATP (final concentration, 6.35 to 510 nM) in modified ATPase buffer at 30°C. The amounts of ADP and total nucleotide were determined following various incubation times as described in Materials and Methods, and the velocity of the ATPase reaction for each [ATP] was calculated. The line drawn on each graph is a best-fit line determined from a least-squares linear regression analysis of the data points.