Literature summary for 3.7.1.11 extracted from

Steinbach, A.; Fraas, S.; Harder, J.; Warkentin, E.; Kroneck, P.M.; Ermler, U.
Crystal structure of a ring-cleaving cyclohexane-1,2-dione hydrolase, a novel member of the thiamine diphosphate enzyme family (2012), FEBS J., 279, 1209-1219.

Activating Compound

Activating Compound	Comment	Organism	Structure
thiamine diphosphate	dependent on, one molecule ThDP per enzyme monomer	Azoarcus sp.

Crystallization (Commentary)

Crystallization (Comment)	Organism
purified CDH from strain 22Lin, hanging drop vapour diffusion method, equal volumes of protein storage and reservoir solution, the latter composed of 60% MPD, 20 mM Na+ acetate and 200 mM NaCl, 25°C, a second cubic crystal form is obtained at 20°C with a reservoir solution containing 17-18% w/v PEG 8000, 100 mM Na+ acetate, 10 mM MnCl2, and 2% w/v isopropanol in 0.1 M HEPES buffer, pH 7.5, X-ray diffraction structure determination and analysis at 1.26 A resolution, modeling	Azoarcus sp.

Crystallization (Comment)

Organism

purified CDH from strain 22Lin, hanging drop vapour diffusion method, equal volumes of protein storage and reservoir solution, the latter composed of 60% MPD, 20 mM Na+ acetate and 200 mM NaCl, 25°C, a second cubic crystal form is obtained at 20°C with a reservoir solution containing 17-18% w/v PEG 8000, 100 mM Na+ acetate, 10 mM MnCl2, and 2% w/v isopropanol in 0.1 M HEPES buffer, pH 7.5, X-ray diffraction structure determination and analysis at 1.26 A resolution, modeling

Azoarcus sp.

Inhibitors

Inhibitors	Comment	Organism	Structure
2-methyl-2,4-pentane-diol	MPD, competitive inhibitor, shows selective binding to the open funnel of CDH and strong binding to the active site. It contacts besides GlyA399 the apolar side chains of PheA259, TrpA285, LeuA551, LeuA487 and LeuA563	Azoarcus sp.

KM Value [mM]

KM Value [mM]	KM Value Maximum [mM]	Substrate	Comment	Organism	Structure
additional information	-	additional information	CDH follows Michaelis-Menten kinetics	Azoarcus sp.
0.0133	-	Cyclohexane-1,2-dione	pH 8.0, 37°C	Azoarcus sp.

Metals/Ions

Metals/Ions	Comment	Organism	Structure
Mg2+	one Mg2+ molecule per enzyme monomer	Azoarcus sp.

Natural Substrates/ Products (Substrates)

Natural Substrates	Organism	Comment (Nat. Sub.)	Natural Products	Comment (Nat. Pro.)	Rev.	Reac.
cyclohexane-1,2-dione + H2O	Azoarcus sp.	-	6-oxohexanoate + ?	further conversion to adipate using NAD+ as electron acceptor	?
cyclohexane-1,2-dione + H2O	Azoarcus sp. 22Lin	-	6-oxohexanoate + ?	further conversion to adipate using NAD+ as electron acceptor	?

Organism

Organism	UniProt	Comment	Textmining
Azoarcus sp.	P0CH62	-	-
Azoarcus sp. 22Lin	P0CH62	-	-

Reaction

Reaction	Comment	Organism	Reaction ID
cyclohexane-1,2-dione + H2O = 6-oxohexanoate	catalytic reaction mechanism, overview	Azoarcus sp.	a

Substrates and Products (Substrate)

Substrates	Comment Substrates	Organism	Products	Comment (Products)	Rev.	Reac.
cyclohexane-1,2-dione + H2O	-	Azoarcus sp.	6-oxohexanoate + ?	further conversion to adipate using NAD+ as electron acceptor	?
cyclohexane-1,2-dione + H2O	-	Azoarcus sp. 22Lin	6-oxohexanoate + ?	further conversion to adipate using NAD+ as electron acceptor	?

Subunits

Subunits	Comment	Organism
tetramer	-	Azoarcus sp.

Synonyms

Synonyms	Comment	Organism
Cdh	-	Azoarcus sp.

Temperature Optimum [°C]

Temperature Optimum [°C]	Temperature Optimum Maximum [°C]	Comment	Organism
37	-	assay at	Azoarcus sp.

Turnover Number [1/s]

Turnover Number Minimum [1/s]	Turnover Number Maximum [1/s]	Substrate	Comment	Organism	Structure
1.6	-	Cyclohexane-1,2-dione	pH 8.0, 37°C	Azoarcus sp.

pH Optimum

pH Optimum Minimum	pH Optimum Maximum	Comment	Organism
8	-	assay at	Azoarcus sp.

Cofactor

Cofactor	Comment	Organism	Structure
FAD	flavoenzyme, the redox-active cofactor FAD seems not to participate in catalysis, one FAD molecule per enzyme monomer. The FAD cofactor is bound in an extended conformation at the C-terminal end of the six-stranded betab-sheet of the domain beta	Azoarcus sp.

General Information

General Information	Comment	Organism
evolution	the ring-cleaving cyclohexane-1,2-dione hydrolase is a member of the thiamine diphosphate enzyme family	Azoarcus sp.
additional information	the active site funnel is rearranged in an unprecedented manner providing the structural basis for the specific binding and cleavage of an alicyclic compound, including a decreased and displaced funnel entrance, a semicircularly shaped loop segment preceding the C-terminal arm and the attachment of the C-terminal arm to other subunits of the CDH tetramer, asymmetry of the two active sites, architecture of the active site funnel of CDH in comparison with other ThDP dependent enzymes, overview	Azoarcus sp.
physiological function	CDH catalyses a key step of an anaerobic degradation pathway for alicyclic alcohols by converting cyclohexane-1,2-dione to 6-oxohexanoate and further to adipate using NAD+ as electron acceptor	Azoarcus sp.

kcat/KM [mM/s]

kcat/KM Value [1/mMs^-1]	kcat/KM Value Maximum [1/mMs^-1]	Substrate	Comment	Organism	Structure
0.0012	-	Cyclohexane-1,2-dione	pH 8.0, 37°C	Azoarcus sp.