TABLE 1.

Kinetic parameters of C. concisus PglC aromatic box variants. Steady‐state kinetic measurements were performed as described in the experimental section and the data were fit using the Michaelis–Menten equation.

Variant	Activity a	Km (μM)	Km 95% CI (μM)	kcat (s−1)	kcat 95% CI (s−1)	kcat/Km (μM−1 s−1)
WT	+++	26.5	(17.6, 40.3)	13.8	(11.8, 16.5)	0.52
W150F	++	24.8	(18.0, 34.3)	1.48	(1.35, 1.63)	0.060
W150Y	++	24.7	(19.8, 30.8)	1.94	(1.81, 2.08)	0.078
W150L	−	n.d.	n.d.	n.d.	n.d.	n.d.
F197W	++	25.7	(17.4, 37.8)	1.32	(1.17, 1.50)	0.052
F197Y	++	20.2	(16.8, 24.3)	1.25	(1.18, 1.33)	0.062
F197A	+	n.d.	n.d.	n.d.	n.d.	n.d.

Note: +++ Activity at 0.3 nM; ++ Activity at 3 nM; + Activity at 30 nM; − No activity at 30 nM.

Abbreviations: n.d., not determined; Cl., confidence limits.

^a The wild‐type level of activity in the presence of 0.3 nM enzyme, to which all variant enzymes are compared, is defined as (+++). A designation of (++) represents the activity of a variant enzyme that attains ~85% of wild‐type activity with 3 nM enzyme. A designation of (+) represents the activity of a variant enzyme that attains ~85% of wild‐type activity with 30 nM enzyme. A designation of (−) is used to describe the activity of a variant enzyme that attains <20% of wild‐type activity with 30 nM enzyme.