Please wait a moment until all data is loaded. This message will disappear when all data is loaded.
Please wait a moment until the data is sorted. This message will disappear when the data is sorted.
Please wait a moment until the data is sorted. This message will disappear when the data is sorted.
4-hydroxybutanoyl-CoA = (E)-but-2-enoyl-CoA + H2O
4-hydroxybutanoyl-CoA = (E)-but-2-enoyl-CoA + H2O
-
-
-
-
4-hydroxybutanoyl-CoA = (E)-but-2-enoyl-CoA + H2O
cleavage is achieved by a FAD-dependent oxidation of 4-hydroxybutanoyl-CoA to 4-hydroxycrotonyl-CoA. In a second step, the hydroxyl group is substituted by a hydride derived from the now reduced FAD in an SN2' reaction leading to vinylacetyl-CoA. Isomerization yields crotonyl-CoA
-
4-hydroxybutanoyl-CoA = (E)-but-2-enoyl-CoA + H2O
mechanism includes a direct dehydration of of 4-hydroxybutanoyl-CoA to vinylacetyl-CoA
-
4-hydroxybutanoyl-CoA = (E)-but-2-enoyl-CoA + H2O
mechanism involves transient one-electron oxidation of the substrate to activate the beta-C-H-bond. the 4Fe-4S-center could serve a structural role and/or as Lewis acid facilitating the leaving of the hydroxyl group
-
4-hydroxybutanoyl-CoA = (E)-but-2-enoyl-CoA + H2O
the pro-(S) hydrogen atom is stereospecifically abstracted from C-3 of 4-hydroxybutanoyl-CoA, and this atom is not returned to C-4
-
4-hydroxybutanoyl-CoA = (E)-but-2-enoyl-CoA + H2O
substrate-induced radical formation in 4-hydroxybutyryl-CoA dehydratase from Clostridium aminobutyricum. The conversion of 4-hydroxybutyryl-CoA to crotonyl-CoA involves the abstraction of the 2Re and 3Si protons. The FAD semiquinone rather than the FAD quinone oxidizes the enolate (or, in the reverse direction, the dienolate) to the enoxy radical (dienoxy radical). The FADH- anion formed, in combination with the T190/E257 dyad, probably acts as a more efficient base to remove the 3Si proton. Reaction mechanism with amino acids proposed to be involved, overview. The release of H2O from Fe1 of the [4Fe-4S]2+ cluster can be facilitated by reduction to [4Fe-4S]+
Please wait a moment until the data is sorted. This message will disappear when the data is sorted.
Please wait a moment until the data is sorted. This message will disappear when the data is sorted.
Please wait a moment until the data is sorted. This message will disappear when the data is sorted.
Please wait a moment until the data is sorted. This message will disappear when the data is sorted.
4-aminobutyryl-CoA
? + H2O
the natural substrate is 4-aminobutyrate
-
-
r
4-hydroxybutanoyl-CoA
(E)-but-2-enoyl-CoA + H2O
4-hydroxybutanoyl-CoA
but-3-enoyl-CoA + H2O
4-hydroxybutanoyl-CoA
crotonyl-CoA + H2O
4-hydroxybutanoyl-CoA
vinylacetyl-CoA + H2O
-
-
-
-
r
4-hydroxybutyryl-CoA
crotonyl-CoA + H2O
-
-
-
r
additional information
?
-
4-hydroxybutanoyl-CoA
(E)-but-2-enoyl-CoA + H2O
-
i.e. crotonyl-CoA
-
?
4-hydroxybutanoyl-CoA
(E)-but-2-enoyl-CoA + H2O
the enzyme is part of autotrophic CO2 fixation pathway in archaea
i.e. crotonyl-CoA
-
?
4-hydroxybutanoyl-CoA
(E)-but-2-enoyl-CoA + H2O
-
i.e. crotonyl-CoA
-
?
4-hydroxybutanoyl-CoA
(E)-but-2-enoyl-CoA + H2O
the enzyme is part of autotrophic CO2 fixation pathway in archaea
i.e. crotonyl-CoA
-
?
4-hydroxybutanoyl-CoA
but-3-enoyl-CoA + H2O
-
reaction involves cleavage of an unactivated C-H bond at the beta-carbon
-
-
r
4-hydroxybutanoyl-CoA
but-3-enoyl-CoA + H2O
-
selective removal of the (2Re)-hydrogen atom. The stereochemical course at C2 and C3 can be described as anti elimination of the two hydrogen atoms, which is identical to that of acyl-CoA dehydrogenases. The formation of the methyl group of crotonyl-CoA from the hydroxymethyl group of 4-hydroxybutanoyl-CoA occurs with retention of configuration
-
-
?
4-hydroxybutanoyl-CoA
but-3-enoyl-CoA + H2O
-
-
-
-
?
4-hydroxybutanoyl-CoA
but-3-enoyl-CoA + H2O
-
-
-
-
?
4-hydroxybutanoyl-CoA
crotonyl-CoA + H2O
-
-
-
?
4-hydroxybutanoyl-CoA
crotonyl-CoA + H2O
the enzyme is involved in the 3-hydroxypropionate/4-hydroxybutyrate carbon fixation pathway
-
-
?
4-hydroxybutanoyl-CoA
crotonyl-CoA + H2O
-
-
-
?
4-hydroxybutanoyl-CoA
crotonyl-CoA + H2O
the enzyme is involved in the 3-hydroxypropionate/4-hydroxybutyrate carbon fixation pathway
-
-
?
additional information
?
-
-
no substrate: cyclopropylcarboxyl-CoA
-
-
?
additional information
?
-
4-hydroxybutyryl-CoA dehydratase (4HBD) from Clostridium aminobutyricum catalyzes the reversible dehydration of 4-hydroxybutyryl-CoA to crotonyl-CoA and the irreversible isomerization of vinylacetyl-CoA to crotonyl-CoA. Specific activity of enzyme 4HBD is measured anaerobically in a coupled assay based on determining the amount of crotonyl-CoA formed by beta-oxidation to acetyl-CoA
-
-
?
additional information
?
-
-
enzyme has an intrinsic vinylacetyl-CoA isomerase activity
-
-
?
Please wait a moment until the data is sorted. This message will disappear when the data is sorted.
Please wait a moment until the data is sorted. This message will disappear when the data is sorted.
[4Fe-4S]-center
the enzyme contains one [4Fe-4S]2x02 cluster per enzyme tetramer, reconstitution of the [4Fe-4S] cluster in the purified enzyme with FeCl3 and Na2S
4Fe-4S-center
-
-
4Fe-4S-center
a [4Fe-4S]2+ cluster, coordinated by three cysteine and one histidine residues, is located 7 A from the Re-side of a flavin adenine dinucleotide moiety
4Fe-4S-center
-
enzyme shows [4Fe-4S]2+ clusters, two clusters/homotetramer. The four iron atoms in each cluster are coordinated in an identical fashion, and there is no direct interaction with substrates. The Fe-S clusters serve a structural rather than a catalytic role in 4-hydroxybutyryl-CoA dehydratase
4Fe-4S-center
-
Fe-S-cluster is difficult to reduce. No equilibration of electrons between the flavin and the Fe-S-center
4Fe-4S-center
-
one 4Fe-4S-center per subunit
FAD
-
2 mol per mol of enzyme
FAD
-
2 mol FAD per mol of enzyme
FAD
a [4Fe-4S]2+cluster, coordinated by three cysteine and one histidine residues, is located 7 A from the Re-side of a flavin adenine dinucleotide moiety
FAD
-
protein-bound FAD, is easily reduced to the semiquinone and only slowly to the hydroquinone. No equilibration of electrons between the flavin and the Fe-S-center
FAD
-
substrate interacts with the flavin. Partial reduction of the enzyme using dithionite results in formation of a neutral flavin semiquinone, which may interact with the 4Fe-4S-center
FAD
one FAD per enzyme subunit, FAD contents of enzyme mutants compared to the wild-type, overview
Please wait a moment until the data is sorted. This message will disappear when the data is sorted.
Please wait a moment until the data is sorted. This message will disappear when the data is sorted.
Please wait a moment until the data is sorted. This message will disappear when the data is sorted.
Please wait a moment until the data is sorted. This message will disappear when the data is sorted.
Please wait a moment until the data is sorted. This message will disappear when the data is sorted.
Please wait a moment until the data is sorted. This message will disappear when the data is sorted.
Please wait a moment until the data is sorted. This message will disappear when the data is sorted.
Please wait a moment until the data is sorted. This message will disappear when the data is sorted.
Please wait a moment until the data is sorted. This message will disappear when the data is sorted.
Please wait a moment until the data is sorted. This message will disappear when the data is sorted.
Please wait a moment until the data is sorted. This message will disappear when the data is sorted.
Please wait a moment until the data is sorted. This message will disappear when the data is sorted.
Please wait a moment until the data is sorted. This message will disappear when the data is sorted.
Please wait a moment until the data is sorted. This message will disappear when the data is sorted.
Please wait a moment until the data is sorted. This message will disappear when the data is sorted.
Please wait a moment until the data is sorted. This message will disappear when the data is sorted.
Please wait a moment until the data is sorted. This message will disappear when the data is sorted.
Please wait a moment until the data is sorted. This message will disappear when the data is sorted.
A460G
site-directed mutagenesis, the mutant shows highly reduced enzyme activity and forms tetramers
C103A
site-directed mutagenesis of a catalytic residue, inactive mutant with monomeric, dimeric, or tetrameric subunit composition compared to wild-type
C299A
site-directed mutagenesis of a catalytic residue, inactive mutant with monomeric, dimeric, or tetrameric subunit composition compared to wild-type
C99A
site-directed mutagenesis of a catalytic residue, inactive mutant with monomeric, dimeric, or tetrameric subunit composition compared to wild-type
E257Q
site-directed mutagenesis, inactive mutant forming tetramers
E455Q
site-directed mutagenesis, inactive mutant forming tetramers
H292C
site-directed mutagenesis of a catalytic residue, inactive mutant with dimeric or tetrameric subunit composition compared to wild-type
H292E
site-directed mutagenesis of a catalytic residue, inactive mutant with tetrameric subunit composition compared to wild-type
K300Q
site-directed mutagenesis, the mutant shows highly reduced enzyme activity and forms tetramers
M149S
site-directed mutagenesis, the mutant shows highly reduced enzyme activity and forms tetramers
Q101E
site-directed mutagenesis, the mutant shows highly reduced enzyme activity and forms tetramers
R90N
site-directed mutagenesis, the mutant shows highly reduced enzyme activity and forms tetramers
Y296F
site-directed mutagenesis, almost inactive mutant forming tetramers
Y296W
site-directed mutagenesis, inactive mutant
additional information
iron and FAD contents of enzyme mutants compared to the wild-type, mutant phenotypes, overview
T190V
site-directed mutagenesis, almost inactive mutant forming tetramers
T190V
site-directed mutagenesis, the mutant shows highly reduced enzyme activity and forms tetramers
Please wait a moment until the data is sorted. This message will disappear when the data is sorted.
Please wait a moment until the data is sorted. This message will disappear when the data is sorted.
Please wait a moment until the data is sorted. This message will disappear when the data is sorted.
Please wait a moment until the data is sorted. This message will disappear when the data is sorted.
Please wait a moment until the data is sorted. This message will disappear when the data is sorted.
Please wait a moment until the data is sorted. This message will disappear when the data is sorted.
Please wait a moment until the data is sorted. This message will disappear when the data is sorted.
Scherf, U.; Shling, B.; Gottschalk, G.; Linder, D.; Buckel, W.
Succinate-ethanol fermentation in Clostridium kluyveri: purification, characterisation of 4-hydroxybutyryl-CoA dehydratase/vinylacetyl-CoA DELTA3-DELTA2-isomerase
Arch. Microbiol.
161
239-245
1994
Clostridium kluyveri
brenda
Scherf, U.; Buckel, W.
Purification and properties of an iron-sulfur and FAD-containing 4-hydroxybutyryl-CoA dehydratase/vinylacetyl-CoA DELTA3-DELTA2-isomerase from Clostridium aminobutyricum
Eur. J. Biochem.
215
421-429
1993
Clostridium aminobutyricum
brenda
Friedrich, P.; Darley, D.J.; Golding, B.T.; Buckel, W.
The complete stereochemistry of the enzymatic dehydration of 4-hydroxybutyryl coenzyme A to crotonyl coenzyme A
Angew. Chem.
47
3254-3257
2008
Clostridium aminobutyricum
brenda
Gerhardt, A.; Cinkaya, I.; Linder, D.; Huisman, G.; Buckel, W.
Fermentation of 4-aminobutyrate by Clostridium aminobutyricum: cloning of two genes involved in the formation and dehydration of 4-hydroxybutyryl-CoA
Arch. Microbiol.
174
189-199
2000
Clostridium aminobutyricum
brenda
Mueh, U.; Cinkaya, I.; Albracht, S.P.J.; Buckel, W.
4-Hydroxybutyryl-CoA dehydratase from Clostridium aminobutyricum: Characterization of FAD and iron-sulfur clusters involved in an overall non-redox reaction
Biochemistry
35
11710-11718
1996
Clostridium aminobutyricum
brenda
Cinkaya, I.; Buckel, W.; Medina, M.; Gomez-Moreno, C.; Cammack, R.
Electron-nuclear double resonance spectroscopy investigation of 4-hydroxybutyryl-CoA dehydratase from Clostridium aminobutyricum: Comparison with other flavin radical enzymes
Biol. Chem.
378
843-849
1997
Clostridium aminobutyricum
brenda
Scott, R.; Naeser, U.; Friedrich, P.; Selmer, T.; Buckel, W.; Golding, B.T.
Stereochemistry of hydrogen removal from the unactivated' C-3 position of 4-hydroxybutyryl-CoA catalysed by 4-hydroxybutyryl-CoA dehydratase
Chem. Commun. (Camb. )
2004
1210-1211
2004
Clostridium aminobutyricum
brenda
Muh, U.; Buckel, W.; Bill, E.
Moessbauer study of 4-hydroxybutyryl-CoA dehydratase. Probing the role of an iron-sulfur cluster in an overall non-redox reaction
Eur. J. Biochem.
248
380-384
1997
Clostridium aminobutyricum
brenda
Willadsen, P.; Buckel, W.
Assay of 4-hydroxybutyryl-CoA dehydratase from Clostridium aminobutyricum
FEMS Microbiol. Lett.
70
187-191
1990
Clostridium aminobutyricum
brenda
Martins, B.M.; Dobbek, H.; Cinkaya, I.; Buckel, W.; Messerschmidt, A.
Crystal structure of 4-hydroxybutyryl-CoA dehydratase: Radical catalysis involving a [4Fe-4S] cluster and flavin
Proc. Natl. Acad. Sci. USA
101
15645-15649
2004
Clostridium aminobutyricum (P55792), Clostridium aminobutyricum
brenda
Berg, I.A.; Kockelkorn, D.; Buckel, W.; Fuchs, G.
A 3-hydroxypropionate/4-hydroxybutyrate autotrophic carbon dioxide assimilation pathway in Archaea
Science
318
1782-1786
2007
Metallosphaera sedula
brenda
Hawkins, A.B.; Adams, M.W.; Kelly, R.M.
Conversion of 4-hydroxybutyrate to acetyl coenzyme A and its anapleurosis in the Metallosphaera sedula 3-hydroxypropionate/4-hydroxybutyrate carbon fixation pathway
Appl. Environ. Microbiol.
80
2536-2545
2014
Metallosphaera sedula (A4YGC7), Metallosphaera sedula, Metallosphaera sedula DSM 5348 (A4YGC7)
brenda
Ramos-Vera, W.H.; Labonte, V.; Weiss, M.; Pauly, J.; Fuchs, G.
Regulation of autotrophic CO2 fixation in the archaeon Thermoproteus neutrophilus
J. Bacteriol.
192
5329-5340
2010
Pyrobaculum neutrophilum (B1YBY6), Pyrobaculum neutrophilum, Pyrobaculum neutrophilum DSM 2338 (B1YBY6)
brenda
Huber, H.; Gallenberger, M.; Jahn, U.; Eylert, E.; Berg, I.A.; Kockelkorn, D.; Eisenreich, W.; Fuchs, G.
A dicarboxylate/4-hydroxybutyrate autotrophic carbon assimilation cycle in the hyperthermophilic archaeum Ignicoccus hospitalis
Proc. Natl. Acad. Sci. USA
105
7851-7856
2008
Ignicoccus hospitalis (A8AA25), Ignicoccus hospitalis, Ignicoccus hospitalis DSM 18386 (A8AA25)
brenda
Zhang, J.; Friedrich, P.; Pierik, A.J.; Martins, B.M.; Buckel, W.
Substrate-induced radical formation in 4-hydroxybutyryl coenzyme A dehydratase from Clostridium aminobutyricum
Appl. Environ. Microbiol.
81
1071-1084
2015
Clostridium aminobutyricum (P55792)
brenda