Literature summary for 4.2.1.46 extracted from

Gross, J.W.; Hegeman, A.D.; Gerratana, B.; Frey, P.A.
Dehydration is catalyzed by glutamate-136 and aspartic acid-135 active site residues in Escherichia coli dTDP-glucose 4,6-dehydratase (2001), Biochemistry, 40, 12497-12504.

Protein Variants

Protein Variants	Comment	Organism
D135135N/E136Q	the turnover number for dTDP-6-fluoro-6-deoxyglucose is 340fold lower than that of the wild-type enzyme, the turnover number for dTDP-glucose is 204fold lower than that of the wild-type enzyme	Escherichia coli
D135A	the steady-state rate of conversion of dTDP-6-fluoro-6-deoxyglucose to dTDP-4-keto-6-deoxyglucose is identical to that of wild-type. The turnover number for dTDP-6-fluoro-6-deoxyglucose is 1.5fold lower than that of the wild-type enzyme, the turnover number for dTDP-glucose is 223fold lower than that of the wild-type enzyme	Escherichia coli
D135N	the steady-state rate of conversion of dTDP-6-fluoro-6-deoxyglucose to dTDP-4-keto-6-deoxyglucose is identical to that of wild-type. The turnover number for dTDP-6-fluoro-6-deoxyglucose is 1.2fold higher than that of the wild-type enzyme, the turnover number for dTDP-glucose is 124fold lower than that of the wild-type enzyme	Escherichia coli
E136A	the turnover number for dTDP-6-fluoro-6-deoxyglucose is 690fold lower than that of the wild-type enzyme, the turnover number for dTDP-glucose is 288fold lower than that of the wild-type enzyme	Escherichia coli
E136Q	the turnover number for dTDP-6-fluoro-6-deoxyglucose is 69fold lower than that of the wild-type enzyme, the turnover number for dTDP-glucose is 67fold lower than that of the wild-type enzyme	Escherichia coli
E198Q	the turnover number for dTDP-6-fluoro-6-deoxyglucose is 190fold lower than that of the wild-type enzyme, the turnover number for dTDP-glucose is 258fold lower than that of the wild-type enzyme	Escherichia coli
K199M	the turnover number for dTDP-6-fluoro-6-deoxyglucose is 260fold lower than that of the wild-type enzyme, the turnover number for dTDP-glucose is 115fold lower than that of the wild-type enzyme	Escherichia coli
K199R	the turnover number for dTDP-6-fluoro-6-deoxyglucose is 680fold lower than that of the wild-type enzyme, the turnover number for dTDP-glucose is 288fold lower than that of the wild-type enzyme	Escherichia coli
Y301F	the turnover number for dTDP-6-fluoro-6-deoxyglucose is 31fold lower than that of the wild-type enzyme, the turnover number for dTDP-glucose is 117fold lower than that of the wild-type enzyme	Escherichia coli

Organism

Organism	UniProt	Comment	Textmining
Escherichia coli	P27830	-	-

Substrates and Products (Substrate)

Substrates	Comment Substrates	Organism	Products	Comment (Products)	Rev.	Reac.
dTDP-6-fluoro-6-deoxyglucose	substrate undergoes fluoride ion elimination instead of dehydration	Escherichia coli	dTDP-4-keto-6-deoxyglucose + F-	-	?
dTDP-glucose	the conversion takes place in three steps: dehydrogenation to dTDP-4-ketoglucose, dehydration to dTDP-4-ketoglucose-5,6-ene and rereduction of C6 to the methyl group. Asp135 and Glu136 are the acid and base catalysts, respectively of the dehydration step	Escherichia coli	dTDP-4-dehydro-6-deoxy-D-glucose + H2O	-	?

Turnover Number [1/s]

Turnover Number Minimum [1/s]	Turnover Number Maximum [1/s]	Substrate	Comment	Organism
0.000064	-	dTDP-6-fluoro-6-deoxyglucose	mutant enzyme E136A	Escherichia coli
0.000065	-	dTDP-6-fluoro-6-deoxyglucose	mutant enzyme K199R	Escherichia coli
0.00013	-	dTDP-6-fluoro-6-deoxyglucose	mutant enzyme D135N/E136Q	Escherichia coli
0.00017	-	dTDP-6-fluoro-6-deoxyglucose	mutant enzyme K199M	Escherichia coli
0.00023	-	dTDP-6-fluoro-6-deoxyglucose	mutant enzyme E198Q	Escherichia coli
0.00064	-	dTDP-6-fluoro-6-deoxyglucose	mutant enzyme E136Q	Escherichia coli
0.0014	-	dTDP-6-fluoro-6-deoxyglucose	mutant enzyme Y301F	Escherichia coli
0.017	-	dTDP-glucose	mutant enzyme E136A	Escherichia coli
0.017	-	dTDP-glucose	mutant enzyme K199R	Escherichia coli
0.019	-	dTDP-glucose	mutant enzyme E198Q	Escherichia coli
0.022	-	dTDP-glucose	mutant enzyme D135A	Escherichia coli
0.024	-	dTDP-glucose	mutant enzyme D135N/E136Q	Escherichia coli
0.029	-	dTDP-6-fluoro-6-deoxyglucose	mutant enzyme D135A	Escherichia coli
0.0395	-	dTDP-glucose	mutant enzyme D135N	Escherichia coli
0.042	-	dTDP-glucose	mutant enzyme Y301F	Escherichia coli
0.0425	-	dTDP-glucose	mutant enzyme K199M	Escherichia coli
0.044	-	dTDP-6-fluoro-6-deoxyglucose	wild-type enzyme	Escherichia coli
0.053	-	dTDP-6-fluoro-6-deoxyglucose	mutant enzyme D135N	Escherichia coli
0.073	-	dTDP-glucose	mutant enzyme E136Q	Escherichia coli
4.9	-	dTDP-glucose	wild-type enzyme	Escherichia coli

Cofactor

Cofactor	Comment	Organism	Structure
NAD+	tightly bound	Escherichia coli