Table 1.

Guanylate cyclase activity of ExoY and different variants

	Activity
ExoY variant	μmol of cGMP/min/mga	% from the WT
WT	74.4 ± 16.0	100.0 ± 21.5
ΔC5	0.4 ± 0.2	0.5 ± 0.3
ΔC9	<0.05	<0.07
F367A	2.2 ± 0.6	3.0 ± 0.8
L371G	8.2 ± 4.2	11.0 ± 5.6
PA14	0.9 ± 0.6	1.2 ± 0.8
PA14–PAO1	75.6 ± 8.7	101.6 ± 11.7

^a Enzymatic activities of WT PAO1 ExoY (WT), C-terminal deletion mutants (ΔC5 and ΔC9), two variants with single mutations (F367A or L371G), a PA14 ExoY variant, and a PAO1–PA14 chimera were measured as described under “Material and Methods” in the presence of 1 μm F-actin and 2 mm GTP. Mean values and standard deviations were calculated as a result of three independent measurements.