>gi|91083623|ref|XP_970124.1| PREDICTED: similar to citrate synthase [Tribolium castaneum] gi|270006831|gb|EFA03279.1| hypothetical protein TcasGA2_TC013214 [Tribolium castaneum]
Citrate synthases (CS) catalyzes the condensation of acetyl coenzyme A (AcCoA) with oxaloacetate (OAA) to form citrate and coenzyme A (CoA), the first step in the citric acid cycle (TCA or Krebs cycle). Some CS proteins function as 2-methylcitrate synthase (2MCS). 2MCS catalyzes the condensation of propionyl-coenzyme A (PrCoA) and OAA to form 2-methylcitrate and CoA during propionate metabolism. The overall CS reaction is thought to proceed through three partial reactions and involves both closed and open conformational forms of the enzyme: a) the carbanion or equivalent is generated from AcCoA by base abstraction of a proton, b) the nucleophilic attack of this carbanion on OAA to generate citryl-CoA, and c) the hydrolysis of citryl-CoA to produce citrate and CoA. There are two types of CSs: type I CS and type II CSs. Type I CSs are found in eukarya, gram-positive bacteria, archaea, and in some gram-negative bacteria and are homodimers with both subunits participating in the active site. Type II CSs are unique to gram-negative bacteria and are homohexamers of identical subunits (approximated as a trimer of dimers). ScCit1 is a nuclear-encoded mitochondrial CS with highly specificity for AcCoA. In addition to its CS function, ScCit1 plays a part in the construction of the TCA cycle metabolon. Yeast cells deleted for Cit1 are hyper-susceptible to apoptosis induced by heat and aging stress. ScCit2 is a peroxisomal CS involved in the glyoxylate cycle; in addition to having activity with AcCoA, it may have activity with PrCoA. Chicken and pig heart CS, two Arabidopsis thaliana (Ath) CSs, CSY4 and -5, and Aspergillus niger (An) CS also belong to this group. Ath CSY4 has a mitochondrial targeting sequence; AthCSY5 has no identifiable targeting sequence. AnCS encoded by the citA gene has both an N-terminal mitochondrial import signal and a C-terminal peroxisiomal target sequence; it is not known if both these signals are functional in vivo. This group contains proteins which functions exclusively as either a CS or a 2MCS, as well as those with relaxed specificity which have dual functions as both a CS and a 2MCS. Length = 427
CS catalyzes the condensation of acetyl coenzyme A (AcCoA) with oxaloacetate (OAA) to form citrate and coenzyme A (CoA), the first step in the citric acid cycle (TCA or Krebs cycle). Some CS proteins function as 2-methylcitrate synthase (2MCS). 2MCS catalyzes the condensation of propionyl-coenzyme A (PrCoA) and OAA to form 2-methylcitrate and CoA during propionate metabolism. The overall CS reaction is thought to proceed through three partial reactions and involves both closed and open conformational forms of the enzyme: a) the carbanion or equivalent is generated from AcCoA by base abstraction of a proton, b) the nucleophilic attack of this carbanion on OAA to generate citryl-CoA, and c) the hydrolysis of citryl-CoA to produce citrate and CoA. There are two types of CSs: type I CS and type II CSs. Type I CSs are found in eukarya, gram-positive bacteria, archaea, and in some gram-negative bacteria and are homodimers with both subunits participating in the active site. Type II CSs are unique to gram-negative bacteria and are homohexamers of identical subunits (approximated as a trimer of dimers). This group includes three S. cerevisiae CS proteins, ScCit1,-2,-3. ScCit1 is a nuclear-encoded mitochondrial CS with highly specificity for AcCoA; in addition to having activity with AcCoA, it plays a part in the construction of the TCA cycle metabolon. Yeast cells deleted for Cit1 are hyper-susceptible to apoptosis induced by heat and aging stress. ScCit2 is a peroxisomal CS involved in the glyoxylate cycle; in addition to having activity with AcCoA, it may have activity with PrCoA. ScCit3 is a mitochondrial CS and functions in the metabolism of PrCoA; it is a dual specificity CS and 2MCS, having similar catalytic efficiency with both AcCoA and PrCoA. The pattern of expression of the ScCIT3 gene follows that of the ScCIT1 gene and its expression is increased in the presence of a ScCIT1 deletion. Included in this group is the Tetrahymena 14 nm filament protein which functions as a CS in mitochondria and as a cytoskeletal component in cytoplasm and Geobacter sulfurreducens (GSu) CS. GSuCS is dimeric and eukaryotic-like; it lacks 2MCS activity and is inhibited by ATP. In contrast to eukaryotic and other prokaryotic CSs, GSuCIT is not stimulated by K+ ions. This group contains proteins which functions exclusively as either a CS or a 2MCS, as well as those with relaxed specificity which have dual functions as both a CS and a 2MCS. Length = 426
This model includes both mitochondrial and peroxisomal forms of citrate synthase. Citrate synthase is the entry point to the TCA cycle from acetyl-CoA. Peroxisomal forms, such as SP:P08679 from yeast (recognized by the C-terminal targeting motif SKL) act in the glyoxylate cycle. Eukaryotic homologs excluded by the high trusted cutoff of this model include a Tetrahymena thermophila citrate synthase that doubles as a filament protein, a putative citrate synthase from Plasmodium falciparum (no TCA cycle), and a methylcitrate synthase from Aspergillus nidulans. Length = 427
2-methylcitrate synthase (2MCS) catalyzes the condensation of propionyl-coenzyme A (PrCoA) and oxaloacetate (OAA) to form 2-methylcitrate and CoA. Citrate synthase (CS) catalyzes the condensation of acetyl coenzyme A (AcCoA) with OAA to form citrate and CoA, the first step in the citric acid cycle (TCA or Krebs cycle). The overall CS reaction is thought to proceed through three partial reactions and involves both closed and open conformational forms of the enzyme: a) the carbanion or equivalent is generated from AcCoA by base abstraction of a proton, b) the nucleophilic attack of this carbanion on OAA to generate citryl-CoA, and c) the hydrolysis of citryl-CoA to produce citrate and CoA. There are two types of CSs: type I CS and type II CSs. Type I CSs are found in eukarya, gram-positive bacteria, archaea, and in some gram-negative bacteria and are homodimers with both subunits participating in the active site. Type II CSs are unique to gram-negative bacteria and are homohexamers of identical subunits (approximated as a trimer of dimers). ScCit3 is mitochondrial and functions in the metabolism of PrCoA; it is a dual specificity CS and 2MCS, having similar catalytic efficiency with both AcCoA and PrCoA. The pattern of expression of the ScCIT3 gene follows that of the major mitochondrial CS gene (CIT1, not included in this group) and its expression is increased in the presence of a CIT1 deletion. This group also contains Aspergillus nidulans 2MCS; a deletion of the gene encoding this protein results in a strain unable to grow on propionate. This group contains proteins which functions exclusively as either a CS or a 2MCS, as well as those with relaxed specificity which have dual functions as both a CS and a 2MCS. Length = 428
>gnl|CDD|99871 cd06118, citrate_synt_like_1, Citrate synthase (CS) catalyzes the condensation of acetyl coenzyme A (AcCoA) and oxalacetate (OAA) to form citrate and coenzyme A (CoA), the first step in the oxidative citric acid cycle (TCA or Krebs cycle)
Score = 75.7 bits (187), Expect = 1e-17
Identities = 28/71 (39%), Positives = 37/71 (52%), Gaps = 8/71 (11%)
Query: 12 RAELPSHVVTMLNNFPNHLHPMSQFSAAITALNSESKFAKAYNDGVHKSKYWEYVYEDSM 71
LP HVV +L+ P + HPM A++AL S FA + K E YE ++
Sbjct: 67 HRALPEHVVEILDLLPKNAHPMDVLRTAVSALGSFDPFA--------RDKSPEARYEKAI 118
Query: 72 DLIAKLPVVAA 82
LIAKLP +AA
Sbjct: 119 RLIAKLPTIAA 129
Peroxisomal CS is involved in the glyoxylate cycle. This group also includes CS proteins which functions as a 2-methylcitrate synthase (2MCS). 2MCS catalyzes the condensation of propionyl-CoA (PrCoA) and OAA to form 2-methylcitrate and CoA during propionate metabolism. This group contains proteins which functions exclusively as either a CS or a 2MCS, as well as those with relaxed specificity which have dual functions as both a CS and a 2MCS. The overall CS reaction is thought to proceed through three partial reactions and involves both closed and open conformational forms of the enzyme: a) the carbanion or equivalent is generated from AcCoA by base abstraction of a proton, b) the nucleophilic attack of this carbanion on OAA to generate citryl-CoA, and c) the hydrolysis of citryl-CoA to produce citrate and CoA. There are two types of CSs: type I CS and type II CSs. Type I CSs are found in eukarya, gram-positive bacteria, archaea, and in some gram-negative bacteria and are homodimers with both subunits participating in the active site. Type II CSs are unique to gram-negative bacteria and are homohexamers of identical subunits (approximated as a trimer of dimers). Some type II CSs are strongly and specifically inhibited by NADH through an allosteric mechanism. Length = 358
CS catalyzes the condensation of acetyl coenzyme A (AcCoA) and oxalacetate (OAA) to form citrate and coenzyme A (CoA), the first step in the citric acid cycle (TCA or Krebs cycle). The overall CS reaction is thought to proceed through three partial reactions and involves both closed and open conformational forms of the enzyme: a) the carbanion or equivalent is generated from AcCoA by base abstraction of a proton, b) the nucleophilic attack of this carbanion on OAA to generate citryl-CoA, and c) the hydrolysis of citryl-CoA to produce citrate and CoA. There are two types of CSs: type I CS and type II CSs. Type I CSs are found in eukarya, gram-positive bacteria, archaea, and in some gram-negative bacteria and are homodimers with both subunits participating in the active site. Type II CSs are unique to gram-negative bacteria and are homohexamers of identical subunits (approximated as a trimer of dimers). Some type II CSs including EcCS are strongly and specifically inhibited by NADH through an allosteric mechanism. Included in this group is an NADH-insensitive type II Acetobacter acetii CS which has retained many of the residues used by EcCS for NADH binding. Length = 400
This model includes both mitochondrial and peroxisomal forms of citrate synthase. Citrate synthase is the entry point to the TCA cycle from acetyl-CoA. Peroxisomal forms, such as SP:P08679 from yeast (recognized by the C-terminal targeting motif SKL) act in the glyoxylate cycle. Eukaryotic homologs excluded by the high trusted cutoff of this model include a Tetrahymena thermophila citrate synthase that doubles as a filament protein, a putative citrate synthase from Plasmodium falciparum (no TCA cycle), and a methylcitrate synthase from Aspergillus nidulans.
Citrate synthases (CS) catalyzes the condensation of acetyl coenzyme A (AcCoA) with oxaloacetate (OAA) to form citrate and coenzyme A (CoA), the first step in the citric acid cycle (TCA or Krebs cycle). Some CS proteins function as 2-methylcitrate synthase (2MCS). 2MCS catalyzes the condensation of propionyl-coenzyme A (PrCoA) and OAA to form 2-methylcitrate and CoA during propionate metabolism. The overall CS reaction is thought to proceed through three partial reactions and involves both closed and open conformational forms of the enzyme: a) the carbanion or equivalent is generated from AcCoA by base abstraction of a proton, b) the nucleophilic attack of this carbanion on OAA to generate citryl-CoA, and c) the hydrolysis of citryl-CoA to produce citrate and CoA. There are two types of CSs: type I CS and type II CSs. Type I CSs are found in eukarya, gram-positive bacteria, archaea, and in some gram-neg
2-methylcitrate synthase (2MCS) catalyzes the condensation of propionyl-coenzyme A (PrCoA) and oxaloacetate (OAA) to form 2-methylcitrate and CoA. Citrate synthase (CS) catalyzes the condensation of acetyl coenzyme A (AcCoA) with OAA to form citrate and CoA, the first step in the citric acid cycle (TCA or Krebs cycle). The overall CS reaction is thought to proceed through three partial reactions and involves both closed and open conformational forms of the enzyme: a) the carbanion or equivalent is generated from AcCoA by base abstraction of a proton, b) the nucleophilic attack of this carbanion on OAA to generate citryl-CoA, and c) the hydrolysis of citryl-CoA to produce citrate and CoA. There are two types of CSs: type I CS and type II CSs. Type I CSs are found in eukarya, gram-positive bacteria, archaea, and in some gram-negative bacteria and are homodimers with both subunits participating in the a
CS catalyzes the condensation of acetyl coenzyme A (AcCoA) with oxaloacetate (OAA) to form citrate and coenzyme A (CoA), the first step in the citric acid cycle (TCA or Krebs cycle). Some CS proteins function as 2-methylcitrate synthase (2MCS). 2MCS catalyzes the condensation of propionyl-coenzyme A (PrCoA) and OAA to form 2-methylcitrate and CoA during propionate metabolism. The overall CS reaction is thought to proceed through three partial reactions and involves both closed and open conformational forms of the enzyme: a) the carbanion or equivalent is generated from AcCoA by base abstraction of a proton, b) the nucleophilic attack of this carbanion on OAA to generate citryl-CoA, and c) the hydrolysis of citryl-CoA to produce citrate and CoA. There are two types of CSs: type I CS and type II CSs. Type I CSs are found in eukarya, gram-positive bacteria, archaea, and in some gram-negative bacteria and are homo
CS catalyzes the condensation of acetyl coenzyme A (AcCoA) and oxalacetate (OAA) to form citrate and coenzyme A (CoA), the first step in the citric acid cycle (TCA or Krebs cycle). The overall CS reaction is thought to proceed through three partial reactions and involves both closed and open conformational forms of the enzyme: a) the carbanion or equivalent is generated from AcCoA by base abstraction of a proton, b) the nucleophilic attack of this carbanion on OAA to generate citryl-CoA, and c) the hydrolysis of citryl-CoA to produce citrate and CoA. There are two types of CSs: type I CS and type II CSs. Type I CSs are found in eukarya, gram-positive bacteria, archaea, and in some gram-negative bacteria and are homodimers with both subunits participating in the active site. Type II CSs are unique to gram-negative bacteria and are homohexamers of ide
>TIGR01798 cit_synth_I citrate synthase I (hexameric type)
This model describes one of several distinct but closely homologous classes of citrate synthase, the protein that brings carbon (from acetyl-CoA) into the TCA cycle. This form, class I, is known to be hexameric and allosterically inhibited by NADH in Escherichia coli, Acinetobacter anitratum, Azotobacter vinelandii, Pseudomonas aeruginosa, etc. In most species with a class I citrate synthase, a dimeric class II isozyme is found. The class II enzyme may act primarily on propionyl-CoA to make 2-methylcitrate or be bifunctional, may be found among propionate utilization enzymes, and may be constitutive or induced by propionate. Some members of this model group as class I enzymes, and may be hexameric, but have shown regulatory properties more like class II enzymes.
CS catalyzes the condensation of acetyl coenzyme A (AcCoA) and oxalacetate (OAA) to form citrate and coenzyme A (CoA), the first step in the citric acid cycle (TCA or Krebs cycle). The overall CS reaction is thought to proceed through three partial reactions and involves both closed and open conformational forms of the enzyme: a) the carbanion or equivalent is generated from AcCoA by base abstraction of a proton, b) the nucleophilic attack of this carbanion on OAA to generate citryl-CoA, and c) the hydrolysis of citryl-CoA to produce citrate and CoA. This group contains three Arabidopsis peroxisomal CS proteins, CYS1, -2, and -3 which are involved in the glyoxylate cycle. AthCYS1, in addition to a peroxisomal targeting sequence, has a predicted secretory signal peptide; it may be targeted to both the secretory pathway and the peroxisomes and is thought to be located in the extracellular matrix. AthCSY1 is expr
CS catalyzes the condensation of acetyl coenzyme A (AcCoA) and oxalacetate (OAA) to form citrate and coenzyme A (CoA), the first step in the citric acid cycle (TCA or Krebs cycle). This group is similar to gram-negative Escherichia coli (Ec) CS (type II, gltA) and Arabidopsis thaliana (Ath) peroxisomal (Per) CS. However EcCS and AthPerCS are not found in this group. The overall CS reaction is thought to proceed through three partial reactions and involves both closed and open conformational forms of the enzyme: a) the carbanion or equivalent is generated from AcCoA by base abstraction of a proton, b) the nucleophilic attack of this carbanion on OAA to generate citryl-CoA, and c) the hydrolysis of citryl-CoA to produce citrate and CoA. There are two types of CSs: type I CS and type II CSs. Type I CSs are found in eukarya, gram-positive bacteria, archaea, and in some gram-negative bacteria and are homodimers w
>cd06112 citrate_synt_like_1_1 Citrate synthase (CS) catalyzes the condensation of acetyl coenzyme A (AcCoA) and oxalacetate (OAA) to form citrate and coenzyme A (CoA), the first step in the oxidative citric acid cycle (TCA or Krebs cycle)
Peroxisomal CS is involved in the glyoxylate cycle. This group also includes CS proteins which functions as a 2-methylcitrate synthase (2MCS). 2MCS catalyzes the condensation of propionyl-CoA (PrCoA) and OAA to form 2-methylcitrate and CoA during propionate metabolism. This group contains proteins which functions exclusively as either a CS or a 2MCS, as well as those with relaxed specificity which have dual functions as both a CS and a 2MCS. The overall CS reaction is thought to proceed through three partial reactions and involves both closed and open conformational forms of the enzyme: a) the carbanion or equivalent is generated from AcCoA by base abstraction of a proton, b) the nucleophilic attack of this carbanion on OAA to generate citryl-CoA, an
2MCS catalyzes the condensation of propionyl-coenzyme A (PrCoA) and oxalacetate (OAA) to form 2-methylcitrate and coenzyme A (CoA) during propionate metabolism. Citrate synthase (CS) catalyzes the condensation of acetyl coenzyme A (AcCoA) and OAA to form citrate and coenzyme A (CoA), the first step in the citric acid cycle (TCA or Krebs cycle). This group contains proteins similar to the E. coli 2MCS, EcPrpC. EcPrpC is one of two CS isozymes in the gram-negative E. coli. EcPrpC is a dimeric (type I ) CS; it is induced during growth on propionate and prefers PrCoA as a substrate, but has a partial CS activity with AcCoA. This group also includes Salmonella typhimurium PrpC and Ralstonia eutropha (Re) 2-MCS1 which are also induced during growth on propionate, prefer PrCoA as substrate, but can also can use AcCoA. Re 2-MCS1 at a low rate can use butyryl-CoA and valeryl-CoA. A second Ralstonia eu
2MCS catalyzes the condensation of propionyl-coenzyme A (PrCoA) and oxalacetate (OAA) to form 2-methylcitrate and coenzyme A (CoA) during propionate metabolism. Citrate synthase (CS) catalyzes the condensation of acetyl coenzyme A (AcCoA) and OAA to form citrate and coenzyme A (CoA), the first step in the citric acid cycle (TCA or Krebs cycle). This group contains proteins similar to the E. coli 2MCS, EcPrpC. EcPrpC is one of two CS isozymes in the gram-negative E. coli. EcPrpC is a dimeric (type I ) CS; it is induced during growth on propionate and prefers PrCoA as a substrate though it has partial CS activity with AcCoA. This group also includes Salmonella typhimurium PrpC and Ralstonia eutropha (Re) 2-MCS1 which are also induced during growth on propionate and prefer PrCoA as substrate, but can also use AcCoA. Re 2-MCS1 can use butyryl-CoA and valeryl-CoA at a lower rate. A second Ralstonia eutropha 2MC
CS catalyzes the condensation of acetyl coenzyme A (AcCoA) and oxalacetate (OAA) to form citrate and coenzyme A (CoA), the first step in the citric acid cycle (TCA or Krebs cycle). The overall CS reaction is thought to proceed through three partial reactions and involves both closed and open conformational forms of the enzyme: a) the carbanion or equivalent is generated from AcCoA by base abstraction of a proton, b) the nucleophilic attack of this carbanion on OAA to generate citryl-CoA, and c) the hydrolysis of citryl-CoA to produce citrate and CoA. There are two types of CSs: type I CS and type II CSs. Type I CSs are found in eukarya, gram-positive bacteria, archaea, and in some gram-negative bacteria and are homodimers with both subunits participating in the active site. Type II CSs are unique to gram-negative bacteria and are homohexamers of identical subunits (approximated as a trimer of dimers). Some typ
3.3.1 from EC is a member of a small family of enzymes that can directly form a carbon-carbon bond without the presence of metal ion cofactors. It catalyses the first reaction in the Krebs' cycle, namely the conversion of oxaloacetate and acetyl-coenzyme A into citrate and coenzyme A. This reaction is important for energy generation and for carbon assimilation. The reaction proceeds via a non-covalently bound citryl-coenzyme A intermediate in a 2-step process (aldol-Claisen condensation followed by the hydrolysis of citryl-CoA). Citrate synthase enzymes are found in two distinct structural types: type I enzymes (found in eukaryotes, Gram-positive bacteria and archaea) form homodimers and have shorter sequences than type II enzymes, which are found in Gram-negative bacteria and are hexameric in structure. In both types, the monomer is composed of two domains: a large alpha-helical domain consisting of two structural repeats, where the second repeat is interrupted by a small alpha-helical domain. The cleft between these domains forms the active site, where both citrate and acetyl-coenzyme A bind. The enzyme undergoes a conformational change upon binding of the oxaloacetate ligand, whereby the active site cleft closes over in order to form the acetyl-CoA binding site []. The energy required for domain closure comes from the interaction of the enzyme with the substrate. Type II enzymes possess an extra N-terminal beta-sheet domain, and some type II enzymes are allosterically inhibited by NADH []. This entry represents types I and II citrate synthase enzymes, as well as the related enzymes 2-methylcitrate synthase and ATP citrate synthase. 2-methylcitrate (2.3.3.5 from EC) synthase catalyses the conversion of oxaloacetate and propanoyl-CoA into (2R,3S)-2-hydroxybutane-1,2,3-tricarboxylate and coenzyme A. This enzyme is induced during bacterial growth on propionate, while type II hexameric citrate synthase is constitutive []. ATP citrate synthase (2.3.3.8 from EC) (also known as ATP citrate lyase) catalyses the MgATP-dependent, CoA-dependent cleavage of citrate into oxaloacetate and acetyl-CoA, a key step in the reductive tricarboxylic acid pathway of CO2 assimilation used by a variety of autotrophic bacteria and archaea to fix carbon dioxide []. ATP citrate synthase is composed of two distinct subunits. In eukaryotes, ATP citrate synthase is a homotetramer of a single large polypeptide, and is used to produce cytosolic acetyl-CoA from mitochondrial produced citrate [].; GO: 0046912 transferase activity, transferring acyl groups, acyl groups converted into alkyl on transfer, 0044262 cellular carbohydrate metabolic process; PDB: 2C6X_D 3L96_B 1OWB_B 1NXG_A 1K3P_A 1OWC_B 3L97_B 1NXE_A 3L98_A 3L99_A ....
>COG0372 GltA Citrate synthase [Energy production and conversion]
>cd06113 citrate_synt_like_1_2 Citrate synthase (CS) catalyzes the condensation of acetyl coenzyme A (AcCoA) and oxalacetate (OAA) to form citrate and coenzyme A (CoA), the first step in the oxidative citric acid cycle (TCA or Krebs cycle)
Peroxisomal CS is involved in the glyoxylate cycle. This group also includes CS proteins which functions as a 2-methylcitrate synthase (2MCS). 2MCS catalyzes the condensation of propionyl-CoA (PrCoA) and OAA to form 2-methylcitrate and CoA during propionate metabolism. This group contains proteins which functions exclusively as either a CS or a 2MCS, as well as those with relaxed specificity which have dual functions as both a CS and a 2MCS. The overall CS reaction is thought to proceed through three partial reactions and involves both closed and open conformational forms of the enzyme: a) a carbanion or equivalent is generated from AcCoA by base abstraction of a proton, b) nucleophilic attack of this carbanion on OAA to generate citryl-CoA, and c) h
CS catalyzes the condensation of acetyl coenzyme A (AcCoA) and oxalacetate (OAA) to form citrate and coenzyme A (CoA), the first step in the citric acid cycle (TCA or Krebs cycle). 2-methylcitrate synthase (2MCS) catalyzes the condensation of propionyl-coenzyme A (PrCoA) and OAA to form 2-methylcitrate and coenzyme A (CoA) during propionate metabolism. The overall CS reaction is thought to proceed through three partial reactions: a) the carbanion or equivalent is generated from AcCoA by base abstraction of a proton, b) the nucleophilic attack of this carbanion on OAA to generate citryl-CoA, and c) the hydrolysis of citryl-CoA to produce citrate and CoA. DsCS, compared with CS from the hyperthermophile Pyrococcus furiosus (not included in this group), has an increase in the size of surface loops, a higher proline content in the loop regions, a more accessible active site, and a highe
CS catalyzes the condensation of acetyl coenzyme A (AcCoA) and oxalacetate (OAA) to form citrate and coenzyme A (CoA), the first step in the citric acid cycle (TCA or Krebs cycle). 2MCS catalyzes the condensation of propionyl-coenzyme A (PrCoA) and OAA to form 2-methylcitrate and coenzyme A (CoA) during propionate metabolism. The overall CS reaction is thought to proceed through three partial reactions and involves both closed and open conformational forms of the enzyme: a) the carbanion or equivalent is generated from AcCoA by base abstraction of a proton, b) the nucleophilic attack of this carbanion on OAA to generate citryl-CoA, and c) the hydrolysis of citryl-CoA to produce citrate and CoA. This group contains proteins similar to BsCS-I, one of two CS isozymes in the gram-positive B. subtilis. The majority of CS activity in B. subtilis is provided by the other isozyme, BsCS-II (not included in this group). BsCS-
>TIGR01800 cit_synth_II 2-methylcitrate synthase/citrate synthase II
Members of this family are dimeric enzymes with activity as 2-methylcitrate synthase, citrate synthase, or both. Many Gram-negative species have a hexameric citrate synthase, termed citrate synthase I (TIGR01798). Members of this family (TIGR01800) appear as a second citrate synthase isozyme but typically are associated with propionate metabolism and synthesize 2-methylcitrate from propionyl-CoA; citrate synthase activity may be incidental. A number of species, including Thermoplasma acidophilum, Pyrococcus furiosus, and the Antarctic bacterium DS2-3R have a bifunctional member of this family as the only citrate synthase isozyme.
>cd06118 citrate_synt_like_1 Citrate synthase (CS) catalyzes the condensation of acetyl coenzyme A (AcCoA) and oxalacetate (OAA) to form citrate and coenzyme A (CoA), the first step in the oxidative citric acid cycle (TCA or Krebs cycle)
Peroxisomal CS is involved in the glyoxylate cycle. This group also includes CS proteins which functions as a 2-methylcitrate synthase (2MCS). 2MCS catalyzes the condensation of propionyl-CoA (PrCoA) and OAA to form 2-methylcitrate and CoA during propionate metabolism. This group contains proteins which functions exclusively as either a CS or a 2MCS, as well as those with relaxed specificity which have dual functions as both a CS and a 2MCS. The overall CS reaction is thought to proceed through three partial reactions and involves both closed and open conformational forms of the enzyme: a) the carbanion or equivalent is generated from AcCoA by base abstraction of a proton, b) the nucleophilic attack of this carbanion on OAA to generate citryl-CoA, and
CS catalyzes the condensation of acetyl coenzyme A (AcCoA) and oxalacetate (OAA) to form citrate and coenzyme A (CoA), the first step in the citric acid cycle (TCA or Krebs cycle). 2MCS catalyzes the condensation of propionyl-coenzyme A (PrCoA) and OAA to form 2-methylcitrate and CoA during propionate metabolism. The overall CS reaction is thought to proceed through three partial reactions: a) the carbanion or equivalent is generated from AcCoA by base abstraction of a proton, b) the nucleophilic attack of this carbanion on OAA to generate citryl-CoA, and c) the hydrolysis of citryl-CoA to produce citrate and CoA. This group contains proteins similar to BsCS-II, the major CS of the gram-positive bacterium Bacillus subtilis. A mutation in the gene which encodes BsCS-II (citZ gene) has been described which resulted in a significant loss of CS activity, partial glutamate auxotrophy, and a sporulation deficiency, a
>pdb|2CTS|A Chain A, Crystallographic Refinement And Atomic Models Of Two Different Forms Of Citrate Synthase At 2.7 And 1.7 Angstroms Resolution Length = 437
>pdb|4CTS|A Chain A, Crystal Structure Analysis And Molecular Model Of A Complex Of Citrate Synthase With Oxaloacetate And S-Acetonyl- Coenzyme A Length = 437
