Table 2 Kinetic parameters of DHS enzymes

From: Coordinated regulation of the entry and exit steps of aromatic amino acid biosynthesis supports the dual lignin pathway in grasses

 

Km PEP

K0.5 E4P

H Coefficient

kcat

kcat/Km (PEP)

kcat/K0.5 (E4P)

IC50

(mM)

(mM)

(only E4P)

(s−1)

(s−1 mM−1)

(s−1 mM−1)

(µM Agn)

(µM Trp)

BdDHS1a

0.13 ± 0.02

0.55 ± 0.04

1.8 ± 0.1

17.0 ± 0.2

126.0 ± 1.7

30.7 ± 0.4

285 ± 24

n.i.

BdDHS1b

0.20 ± 0.07

0.40 ± 0.02

2.1 ± 0.1

11.3 ± 0.1

57.2 ± 0.3

28.3 ± 0.1

n.i.

n.i.

BdDHS2

0.19 ± 0.01

0.51 ± 0.10

1.5 ± 0.6

5.6  ± 0.01

29.0 ± 0.1

10.8 ± 0.01

91 ± 11

120 ± 4

  1. Original data for the determination of the kinetic parameters Km/K0.5 and kcat are shown in Supplemental Fig. S9. kcat/Km was calculated as described for TyrA enzymes in the legend of Table 1. IC50 for tryptophan and arogenate were determined based on the original data shown in main Fig. 4D, F, respectively. n.i. = not inhibited. All data are means ± SD of n = 4 − 6 derived from at least two independent experiments conducted on different days using different batches of purified recombinant enzyme. PEP phosphoenolpyruvate, E4P erythrose 4-phosphate.
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