TABLE 3.

Effect of ATPase inhibitors on cytExeA ATPase activity

Compound	% cytExeA ATPase activitya	Specific forb
None	100
0.4 mM vanadate	97	P, I
10 mM KNO3	74	V
10 mM NaN3	10	F, A
10 μM DCCDc	76	F, P, V
5 mM DCCDc	8	F, P, V
1 mM AMP-PNPd	12	F, V

^aATPase activity was measured using the malachite green method under standard conditions with 2.5 mM MgCl₂ and 4 mM ATP. cytExeA was preincubated with the compounds for 10 minutes prior to the addition of ATP.

^bP, phosphorylation-type ATPase; V, vacuolar-type ATPase; F, F_o F₁-type ATPase; A, SecA component of the Sec translocase; I, ATPase of the bacterial type I extracellular secretory pathway (or ABC ATPase).

^cDCCD, 1,3-dicyclohexylcarbodiimide.

^dAMP-PNP, 5′-adenylylimidodiphosphate.