Table 3.

Inhibition kinetic parameters.

Enzyme	I0.5 (mM)	nH
OtaS/OtaL	0.179 ± 0.004	1.9
OtaS/OtaLR466K	0.139 ± 0.004	1.6
OtaSK443R/OtaL	1.6 ± 0.2	1.7
OtaSK443R/OtaLR466K	0.75 ± 0.08	1.4

Saturation curves for Pi were performed at the A_0.5 for 3PGA of each enzyme (see Table 2). Enzyme activity was assayed using the radioactive method, as described in Section “Materials and Methods.”