Table 4.

Steady State Kinetic Constants of SaDHNA and Site-Directed Mutants

		SaDHNA	SaE22A	SaE74A	SaK100A	SaK100Q
DHNP	kcat (s−1)	0.045±0.002	(9.3±0.4)×10−6	n.d.a	(2.2±0.1)×10−6	(1.6±0.3)×10−5
	Km (μM)	4.6±0.3	3.9±0.6	n.d.	5.8±1	n.d.
	kcat/Km (s−1M−1)	9.7	2.4×10−3	(1.7±0.09)×10−2	3.7×10−4
DHMP	kcat (s−1)	0.01±0.001	(6.5±0.2)×10−6	n.d.	(5.1±0.1)×10−6	(5.7±0.9)×10−6
	Km (μM)	5.5±0.2	4.0±0.6	n.d.	9.5±0.7	n.d.
	kcat/Km (s−1M−1)	1.8	1.6×10−3	(8.0±0.08)×10−2	5.4×10−4

^an.d.: not determined.