Table 2.

DNA cleavage by Cfr42I with different metal-ion cofactors

Metal-ion cofactor	k1, s−1a	k2, s−1b
Mg2+ (10 mM)	0.78 ± 0.05	0.29 ± 0.05
Co2+ (10 mM)	2.40 ± 0.04	0.37 ± 0.03
Mn2+ (10 mM)	0.95 ± 0.06	0.17 ± 0.01
Ca2+ (10 mM)	0.0027 ± 0.0002	0.0020 ± 0.0003
Cu2+ (1 mM)	0.0010 ± 0.0001	0.0003 ± 0.0001
Zn2+ (0.1 mM)	0.036 ± 0.001	0.017 ± 0.002
Ni2+ (0.1 mM)	0.026 ± 0.002	0.010 ± 0.002

^ak₁ is the rate constant for the first DNA-strand nicking determined by fitting Equation (1) to experimental data.

^bk₂ is the rate constant for the second DNA-strand cleavage determined by fitting Equation (1) to experimental data.