Table 1.

Kinetic constants for wild-type and mutant DUBm cleavage of Ub-AMC See also Figure S1.

DUB module mutant	kcat (sec−1)	KM (µM)	kcat/ KM (M−1 sec−1)	Critical χ2
WT	4.4 ± 0.3	24 ± 2	(1.8 ± 0.2) × 105	3.1 × 10−2
S144N	6.5 ± 0.3	28 ± 2	(2.3 ± 0.2) × 105	2.0 × 10−2
S149N	3.1 ± 0.2	20 ± 2	(1.6 ± 0.2) × 105	2.2 × 10−2
ΔZnF	0.063 ± 0.01	19 ± 1	(3.3 ± 0.4) × 103	3.1 × 10−5
ΔZnF S144N	0.28 ± 0.02	17 ± 2	(1.6 ± 0.2) × 104	4.5 × 10−4
ΔZnF S149N	0.26 ± 0.02	11 ± 1	(2.4 ± 0.3) × 104	5.9 × 10−4
ΔZnF S144N S149N	0.47 ± 0.02	13 ± 1	(3.6 ± 0.3) × 104	1.1 × 10−3