UniProt functional annotation for P0AGE9



	UniProt functional annotation for P0AGE9

UniProt code: P0AGE9.

Organism: Escherichia coli (strain K12).

Taxonomy: Bacteria; Proteobacteria; Gammaproteobacteria; Enterobacterales; Enterobacteriaceae; Escherichia.

Function: Succinyl-CoA synthetase functions in the citric acid cycle (TCA), coupling the hydrolysis of succinyl-CoA to the synthesis of either ATP or GTP and thus represents the only step of substrate-level phosphorylation in the TCA. The alpha subunit of the enzyme binds the substrates coenzyme A and phosphate, while succinate binding and nucleotide specificity is provided by the beta subunit. Can use either ATP or GTP, but prefers ATP. It can also function in the other direction for anabolic purposes, and this may be particularly important for providing succinyl-CoA during anaerobic growth when the oxidative route from 2-oxoglutarate is severely repressed. {ECO:0000255|HAMAP- Rule:MF_01988, ECO:0000269|PubMed:10353839}.

Catalytic activity: Reaction=ATP + CoA + succinate = ADP + phosphate + succinyl-CoA; Xref=Rhea:RHEA:17661, ChEBI:CHEBI:30031, ChEBI:CHEBI:30616, ChEBI:CHEBI:43474, ChEBI:CHEBI:57287, ChEBI:CHEBI:57292, ChEBI:CHEBI:456216; EC=6.2.1.5; Evidence={ECO:0000255|HAMAP- Rule:MF_01988, ECO:0000269|PubMed:10353839};

Activity regulation: Exhibits two interesting properties: 'substrate synergism', in which the enzyme is most active for the catalysis of its partial reactions only when all the substrate-binding sites are occupied, and 'catalytic cooperativity' between alternating active sites in the tetramer, whereby the interaction of substrates (particularly ATP) at one site is needed to promote catalysis at the other.

Biophysicochemical properties: Kinetic parameters: KM=0.25 mM for succinate {ECO:0000269|PubMed:10353839}; KM=4 uM for CoA {ECO:0000269|PubMed:10353839}; Note=kcat is 2684 min(-1) with ATP as substrate and 1471 min(-1) with GTP as substrate. {ECO:0000269|PubMed:10353839};

Pathway: Carbohydrate metabolism; tricarboxylic acid cycle; succinate from succinyl-CoA (ligase route): step 1/1. {ECO:0000255|HAMAP- Rule:MF_01988, ECO:0000305|PubMed:10353839}.

Subunit: Heterotetramer of two alpha and two beta subunits. {ECO:0000255|HAMAP-Rule:MF_01988, ECO:0000269|PubMed:8144675, ECO:0000269|PubMed:9917402}.

Miscellaneous: Succinyl-CoA synthetase (SCS) of E.coli catalyzes its reaction via three steps that involve phosphoryl enzyme and enzyme- bound succinyl phosphate as intermediates.

Similarity: Belongs to the succinate/malate CoA ligase alpha subunit family. {ECO:0000255|HAMAP-Rule:MF_01988}.

Annotations taken from UniProtKB at the EBI.


Organism:		Escherichia coli (strain K12).
Taxonomy:		Bacteria; Proteobacteria; Gammaproteobacteria; Enterobacterales; Enterobacteriaceae; Escherichia.



Function:		Succinyl-CoA synthetase functions in the citric acid cycle (TCA), coupling the hydrolysis of succinyl-CoA to the synthesis of either ATP or GTP and thus represents the only step of substrate-level phosphorylation in the TCA. The alpha subunit of the enzyme binds the substrates coenzyme A and phosphate, while succinate binding and nucleotide specificity is provided by the beta subunit. Can use either ATP or GTP, but prefers ATP. It can also function in the other direction for anabolic purposes, and this may be particularly important for providing succinyl-CoA during anaerobic growth when the oxidative route from 2-oxoglutarate is severely repressed. {ECO:0000255\|HAMAP- Rule:MF_01988, ECO:0000269\|PubMed:10353839}.


Catalytic activity:		Reaction=ATP + CoA + succinate = ADP + phosphate + succinyl-CoA; Xref=Rhea:RHEA:17661, ChEBI:CHEBI:30031, ChEBI:CHEBI:30616, ChEBI:CHEBI:43474, ChEBI:CHEBI:57287, ChEBI:CHEBI:57292, ChEBI:CHEBI:456216; EC=6.2.1.5; Evidence={ECO:0000255\|HAMAP- Rule:MF_01988, ECO:0000269\|PubMed:10353839};
Activity regulation:		Exhibits two interesting properties: 'substrate synergism', in which the enzyme is most active for the catalysis of its partial reactions only when all the substrate-binding sites are occupied, and 'catalytic cooperativity' between alternating active sites in the tetramer, whereby the interaction of substrates (particularly ATP) at one site is needed to promote catalysis at the other.
Biophysicochemical properties:		Kinetic parameters: KM=0.25 mM for succinate {ECO:0000269\|PubMed:10353839}; KM=4 uM for CoA {ECO:0000269\|PubMed:10353839}; Note=kcat is 2684 min(-1) with ATP as substrate and 1471 min(-1) with GTP as substrate. {ECO:0000269\|PubMed:10353839};
Pathway:		Carbohydrate metabolism; tricarboxylic acid cycle; succinate from succinyl-CoA (ligase route): step 1/1. {ECO:0000255\|HAMAP- Rule:MF_01988, ECO:0000305\|PubMed:10353839}.
Subunit:		Heterotetramer of two alpha and two beta subunits. {ECO:0000255\|HAMAP-Rule:MF_01988, ECO:0000269\|PubMed:8144675, ECO:0000269\|PubMed:9917402}.
Miscellaneous:		Succinyl-CoA synthetase (SCS) of E.coli catalyzes its reaction via three steps that involve phosphoryl enzyme and enzyme- bound succinyl phosphate as intermediates.
Similarity:		Belongs to the succinate/malate CoA ligase alpha subunit family. {ECO:0000255\|HAMAP-Rule:MF_01988}.