TABLE 2.

Kinetics parameters in thiosulfate-dependent cyt c₅₅₄ reduction activities^a

Component	V (μmol cyt c554 reduction · μmol Sox protein−1 · min−1)	Km (mM)
SoxYZ, SoxB, and SoxAX-CT1020 protein	7.9 ± 0.2	0.17 ± 0.02
SoxYZ, SoxB, and rSoxAX-rCT1020	7.8 ± 0.1	0.18 ± 0.02
SoxYZ, SoxB, rSoxA, and rSoxX	0.24 ± 0.08	0.16 ± 0.02
SoxYZ and SoxB	ND
SoxYZ and SoxAX-CT1020 protein	ND
SoxB and SoxAX-CT1020 protein	ND

^aThiosulfate-dependent cyt c₅₅₄ reduction activities and K_m values were determined from the [S]₀/v-versus-[S]₀ plot in the thiosulfate concentration range of 0 to 2 mM. The values are the means ± standard deviations of the results of three independent measurements similar to the ones whose results are shown in Fig. 4a and b. ND, not detectable (<0.01 μmol cyt c₅₅₄ reduced · μmol Sox protein⁻¹ · min⁻¹).