ENZYME entry: EC 18.104.22.168
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|(R)-2-hydroxyacyl-CoA dehydratase activating ATPase.
|(R)-2-hydroxyacyl-CoA dehydratase activase.|
|2 ATP + a reduced flavodoxin + an inactive (R)-2-hydroxyacyl-CoA dehydratase + 2 H(2)O <=> 2 ADP + 2 phosphate + a flavodoxin semiquinone + an active (R)-2-hydroxyacyl-CoA dehydratase|
- Members of the (R)-2-hydroxyacyl-CoA dehydratase family (including
EC 22.214.171.124, EC 126.96.36.199, EC 188.8.131.52 and EC 184.108.40.206) are two-
component systems composed of an activator component and a
- The activator is an extremely oxygen-sensitive homodimer with one
[4Fe-4S] cluster bound at the dimer interface.
- Before it can catalyze the dehydration reaction, the dehydratase
requires one high-energy electron that is used to transiently reduce
the electrophilic thiol ester carbonyl to a nucleophilic ketyl
radical anion, facilitating the elimination of the hydroxyl group.
- The activator, which has been named archerase because its open
position resembles an archer shooting arrows, binds two ADP
- Upon the reduction of its [4Fe-4S] cluster by a single electron,
delivered by a dedicated flavodoxin or a clostridial ferredoxin,
the two ADP molecules exchange for two ATP molecules, resulting in a
large conformational change.
- The change allows the activator to bind to the dehydratase component
and transfer the electron to it, activating it.
- During this event the two ATP molecules are hydrolyzed and the
activator returns to its resting state.
- Since the electron is regenerated at the end of each reaction cycle
of the dehydratase, the activation is required only once, before the
first reaction takes place.
|PRIAM enzyme-specific profiles||220.127.116.11|
|KEGG Ligand Database for Enzyme Nomenclature||18.104.22.168|
|IUBMB Enzyme Nomenclature||22.214.171.124|
|MEDLINE||Find literature relating to 126.96.36.199|
|Rhea expert-curated reactions||188.8.131.52|
entries corresponding to 5.6.1.-
All ENZYME / UniProtKB/Swiss-Prot entries corresponding to 5.6.-.-
All ENZYME / UniProtKB/Swiss-Prot entries corresponding to 5.-.-.-