| Isochorismate synthase | |||||||||
|---|---|---|---|---|---|---|---|---|---|
 Ishochorismate Synthase cartoon view (2 subunits) | |||||||||
| Identifiers | |||||||||
| EC no. | 5.4.4.2 | ||||||||
| CAS no. | 37318-53-9 | ||||||||
| Databases | |||||||||
| IntEnz | IntEnz view | ||||||||
| BRENDA | BRENDA entry | ||||||||
| ExPASy | NiceZyme view | ||||||||
| KEGG | KEGG entry | ||||||||
| MetaCyc | metabolic pathway | ||||||||
| PRIAM | profile | ||||||||
| PDB structures | RCSB PDB PDBe PDBsum | ||||||||
| |||||||||
Isochorismate synthase ( EC 5.4.4.2) is an isomerase enzyme that catalyzes the first step in the biosynthesis of vitamin K2 (menaquinone) in Escherichia coli . [1]
Isochorismate synthase, belongs to the isomerase enzyme family. More specifically it is classified as an intramolecular transferase because it transfers the hydroxy group of chorismate between carbons. [2]
Isochorismate synthase catalyzes the irreversible conversion of chorismate to isochorismate:
Isochorismate synthase is most active at 37 °C and at a pH between 7.5 and 8. It requires Mg2+ as a cofactor, in a concentration between 100 μM and 1 mM. [1] Inhibitors of isochorismate synthase include:
The systematic name of this enzyme is isochorismate hydroxymutase, and the common name is isochorismate synthase. Other names for this enzyme include:
MenF is a gene that codes for the isochorismate synthase found in the menaquinone pathway in Escherichia coli, not to be mistaken for the entC gene that codes for the isochorismate synthase found in the enterobactin pathway in Escherichia coli. [1] This enzyme catalyzes the first step in the biosynthesis of salicylic acid in Pseudomonas aeruginosa . [4] Isochorismate synthase has several other homologs that are found in other organisms. These include:
| Enzyme Genes/Enzyme Names | Organisms |
|---|---|
| ICS |
|
| ICS1 |
|
| ICS1 gene product |
|
| ICS2 |
|
| Isochorismate synthase |
|
| Isochorismate synthase 1 |
|
| Mbtl |
|
| PchA |
|
Chorismic acid, more commonly known as its anionic form chorismate, is an important biochemical intermediate in plants and microorganisms. It is a precursor for:
Amino acid synthesis is the set of biochemical processes by which the amino acids are produced. The substrates for these processes are various compounds in the organism's diet or growth media. Not all organisms are able to synthesize all amino acids. For example, humans can synthesize 11 of the 20 standard amino acids. These 11 are called the non-essential amino acids).
The enzyme Phosphoribosylaminoimidazole carboxylase, or AIR carboxylase (EC 4.1.1.21) is involved in nucleotide biosynthesis and in particular in purine biosynthesis. It catalyzes the conversion of 5'-phosphoribosyl-5-aminoimidazole ("AIR") into 5'-phosphoribosyl-4-carboxy-5-aminoimidazole ("CAIR") as described in the reaction:
The crotonase family comprises mechanistically diverse proteins that share a conserved trimeric quaternary structure, the core of which consists of 4 turns of a (beta/beta/alpha)n superhelix.
In enzymology, a 5-(carboxyamino)imidazole ribonucleotide mutase is an enzyme that catalyzes the chemical reaction
In enzymology, a phosphoribosylanthranilate isomerase (PRAI) is an enzyme that catalyzes the third step of the synthesis of the amino acid tryptophan.
In enzymology, an isochorismatase (EC 3.3.2.1) is an enzyme that catalyzes the chemical reaction
The enzyme 5-oxopent-3-ene-1,2,5-tricarboxylate decarboxylase (EC 4.1.1.68) catalyzes the chemical reaction
The enzyme anthranilate synthase catalyzes the chemical reaction
The enzyme indole-3-glycerol-phosphate synthase (IGPS) (EC 4.1.1.48) catalyzes the chemical reaction
The enzyme 1,4-dihydroxy-2-naphthoyl-CoA synthase catalyzes the sixth step in the biosynthesis of phylloquinone and menaquinone, the two forms of vitamin K. In E. coli, 1,4-dihydroxy-2-naphthoyl-CoA synthase, formerly known as naphthoate synthase, is encoded by menB and uses O-succinylbenzoyl-CoA as a substrate and converts it to 1,4-dihydroxy-2-naphthoyl-CoA.
In enzymology, an aminodeoxychorismate synthase is an enzyme that catalyzes the chemical reaction
o-Succinylbenzoate—CoA ligase, encoded from the menE gene in Escherichia coli, catalyzes the fifth reaction in the synthesis of menaquinone. This pathway is called 1, 4-dihydroxy-2-naphthoate biosynthesis I. Vitamin K is a quinone that serves as an electron transporter during anaerobic respiration. This process of anaerobic respiration allows the bacteria to generate the energy required to survive.
The enzyme chorismate synthase catalyzes the chemical reaction
2-Succinyl-6-hydroxy-2,4-cyclohexadiene-1-carboxylate synthase, also known as SHCHC synthase is encoded by the menH gene in Escherichia coli and functions in the synthesis of vitamin K. The specific step in the synthetic pathway that SHCHC synthase catalyzes is the conversion of 5-enolpyruvoyl-6-hydroxy-2-succinylcyclohex-3-ene-1-carboxylate to (1R,6R)-6-hydroxy-2-succinylcyclohexa-2,4-diene-1-carboxylate and pyruvate.
(6S)-6-Fluoroshikimic acid is an antibacterial agent acting on the aromatic biosynthetic pathway. It may be used against Plasmodium falciparum, the causative agent of malaria. The molecule is targeting the enzymes of the shikimate pathway. This metabolic pathway is not present in mammals. The mechanism of action of the molecule is not through the inhibition of chorismate synthase but by the inhibition of 4-aminobenzoic acid synthesis.
In enzymology, SEPHCHC synthase (EC EC 2.2.1.9), encoded by menD gene in E. coli, is an enzyme that catalyzes the second step of menaquinone (vitamin K2) biosynthesis. The two substrates of this enzyme are 2-oxoglutarate and isochorismate. The products of this enzyme are 5-enolpyruvoyl-6-hydroxy-2-succinyl-cyclohex-3-ene-1-carboxylate and CO2. It belongs to the transferase family.
1-4-dihydroxy-2-napthoate (DHNA) polyprenyltransferase (EC 2.5.1.74)is an enzyme that catalyzes the chemical reaction: all-trans-nonaprenyl diphosphate + 1-4-dihydroxy-2-napthoate + H+ demethylmenaquinol-9 + diphosphate + carbon dioxide
o-Succinylbenzoate synthase (OSBS) (EC 4.2.1.113) is an enzyme encoded by the menC gene in E.coli, and catalyzes the dehydration of 2-succinyl-6-hydroxy-2,4-cyclohexadiene-1-carboxylate (SHCHC) to form 4-(2'-carboxyphenyl)-4-oxobutyrate, also called o-succinylbenzoate or OSB, hence the name of the enzyme. This reaction is the fourth step in the menaquinone biosynthetic pathway, which is used by bacteria to synthesize menaquinone, also known as vitamin K2.
Isochorismate pyruvate lyase is an enzyme responsible for catalyzing part of the pathway involved in the formation of salicylic acid. More specifically, IPL will use isochorismate as a substrate and convert it into salicylate and pyruvate. IPL is a PchB enzyme originating from the pchB gene in Pseudomonas aeruginosa.
