Table 1. Chorismate mutase activity of wild-type MtCM (wt) and selected MtCM library variants.^a.

Variant	C-Terminal positions 84–90b	k cat/K m (M-1 s-1)c	Fold activation by MtDSd	Remaining activity of complex +Phe +Tyr (%)e
wt	GRGRLGH	790±120	131±43	7.8±2.3
1–6	GRGPL*	1350±200	4.5±1.0	45±10
2–8	GRGHL*	1050±160	4.8±1.0	18±5
3–16	GRGHLGH	1150±170	82±16	3.7±0.8
4–4	GRGILGH	640±100	24±4	3.6±1.7
4–5	GRGKLGH	630±100	106±16	4.1±0.9
2–4	GRGKLGT	620±90	40±7	7.0±1.2
ST–46	GRGRLTR	870±130	7.9±2.0	14±6
2–17	GRGQLGC	1150±170	6.7±1.1	22±3

^aDetails to the assay conditions and calculation of individual parameters and their standard deviations are provided in Materials and Methods.

^bAn asterisk indicates premature termination (the last residue is Leu88 for variants 1–6 and 2–8).

^cCatalytic efficiency of MtCM variant alone (in the absence of MtDS).

^dThe apparent activation factor was estimated as described previously [10], as the ratio of CM initial velocities of the MtCM-MtDS complex (v _{0 (MtDS+MtCM)}), normalized by MtCM-variant and chorismate concentrations, over k _cat/K _m for free MtCM.

^eRatio of initial velocity v _{0 (MtDS+MtCM)} as in footnote ^c, but measured in the presence of 100 µM Phe and 100 µM Tyr, divided by v _{0 (MtDS+MtCM)} obtained in the absence of these feedback inhibitors.