N-acetylserine-responsive cysteine regulon transcriptional activator; This protein is a positive regulator of gene expression for the cysteine regulon, a system of 10 or more loci involved in the biosynthesis of L-cysteine from inorganic sulfate. The inducer for CysB is N-acetylserine. CysB inhibits its own transcription.

Sulfite reductase, beta subunit, NAD(P)-binding, heme-binding; Component of the sulfite reductase complex that catalyzes the 6-electron reduction of sulfite to sulfide. This is one of several activities required for the biosynthesis of L-cysteine from sulfate. Belongs to the nitrite and sulfite reductase 4Fe-4S domain family.

N-acetylserine-responsive cysteine regulon transcriptional activator; This protein is a positive regulator of gene expression for the cysteine regulon, a system of 10 or more loci involved in the biosynthesis of L-cysteine from inorganic sulfate. The inducer for CysB is N-acetylserine. CysB inhibits its own transcription.

Sulfite reductase, alpha subunit, flavoprotein; Component of the sulfite reductase complex that catalyzes the 6-electron reduction of sulfite to sulfide. This is one of several activities required for the biosynthesis of L-cysteine from sulfate. The flavoprotein component catalyzes the electron flow from NADPH -> FAD -> FMN to the hemoprotein component; In the N-terminal section; belongs to the flavodoxin family.

Sulfite reductase, beta subunit, NAD(P)-binding, heme-binding; Component of the sulfite reductase complex that catalyzes the 6-electron reduction of sulfite to sulfide. This is one of several activities required for the biosynthesis of L-cysteine from sulfate. Belongs to the nitrite and sulfite reductase 4Fe-4S domain family.

N-acetylserine-responsive cysteine regulon transcriptional activator; This protein is a positive regulator of gene expression for the cysteine regulon, a system of 10 or more loci involved in the biosynthesis of L-cysteine from inorganic sulfate. The inducer for CysB is N-acetylserine. CysB inhibits its own transcription.

Sulfite reductase, beta subunit, NAD(P)-binding, heme-binding; Component of the sulfite reductase complex that catalyzes the 6-electron reduction of sulfite to sulfide. This is one of several activities required for the biosynthesis of L-cysteine from sulfate. Belongs to the nitrite and sulfite reductase 4Fe-4S domain family.

Sulfite reductase, alpha subunit, flavoprotein; Component of the sulfite reductase complex that catalyzes the 6-electron reduction of sulfite to sulfide. This is one of several activities required for the biosynthesis of L-cysteine from sulfate. The flavoprotein component catalyzes the electron flow from NADPH -> FAD -> FMN to the hemoprotein component; In the N-terminal section; belongs to the flavodoxin family.

Sulfite reductase, beta subunit, NAD(P)-binding, heme-binding; Component of the sulfite reductase complex that catalyzes the 6-electron reduction of sulfite to sulfide. This is one of several activities required for the biosynthesis of L-cysteine from sulfate. Belongs to the nitrite and sulfite reductase 4Fe-4S domain family.

Thiosulfate:cyanide sulfurtransferase (rhodanese); Catalyzes, although with low efficiency, the sulfur transfer reaction from thiosulfate to cyanide. The relatively low affinity of GlpE for both thiosulfate and cyanide suggests that these compounds are not the physiological substrates. Thioredoxin 1 or related dithiol proteins could instead be the physiological sulfur-acceptor substrate. Possible association with the metabolism of glycerol-phosphate remains to be elucidated.

Sulfite reductase, beta subunit, NAD(P)-binding, heme-binding; Component of the sulfite reductase complex that catalyzes the 6-electron reduction of sulfite to sulfide. This is one of several activities required for the biosynthesis of L-cysteine from sulfate. Belongs to the nitrite and sulfite reductase 4Fe-4S domain family.

Cystathionine gamma-synthase, PLP-dependent; Catalyzes the formation of L-cystathionine from O-succinyl-L- homoserine (OSHS) and L-cysteine, via a gamma-replacement reaction. In the absence of thiol, catalyzes gamma-elimination to form 2- oxobutanoate, succinate and ammonia.

Sulfite reductase, alpha subunit, flavoprotein; Component of the sulfite reductase complex that catalyzes the 6-electron reduction of sulfite to sulfide. This is one of several activities required for the biosynthesis of L-cysteine from sulfate. The flavoprotein component catalyzes the electron flow from NADPH -> FAD -> FMN to the hemoprotein component; In the N-terminal section; belongs to the flavodoxin family.

N-acetylserine-responsive cysteine regulon transcriptional activator; This protein is a positive regulator of gene expression for the cysteine regulon, a system of 10 or more loci involved in the biosynthesis of L-cysteine from inorganic sulfate. The inducer for CysB is N-acetylserine. CysB inhibits its own transcription.

Sulfite reductase, alpha subunit, flavoprotein; Component of the sulfite reductase complex that catalyzes the 6-electron reduction of sulfite to sulfide. This is one of several activities required for the biosynthesis of L-cysteine from sulfate. The flavoprotein component catalyzes the electron flow from NADPH -> FAD -> FMN to the hemoprotein component; In the N-terminal section; belongs to the flavodoxin family.

Sulfite reductase, beta subunit, NAD(P)-binding, heme-binding; Component of the sulfite reductase complex that catalyzes the 6-electron reduction of sulfite to sulfide. This is one of several activities required for the biosynthesis of L-cysteine from sulfate. Belongs to the nitrite and sulfite reductase 4Fe-4S domain family.

Sulfite reductase, alpha subunit, flavoprotein; Component of the sulfite reductase complex that catalyzes the 6-electron reduction of sulfite to sulfide. This is one of several activities required for the biosynthesis of L-cysteine from sulfate. The flavoprotein component catalyzes the electron flow from NADPH -> FAD -> FMN to the hemoprotein component; In the N-terminal section; belongs to the flavodoxin family.

Thiosulfate:cyanide sulfurtransferase (rhodanese); Catalyzes, although with low efficiency, the sulfur transfer reaction from thiosulfate to cyanide. The relatively low affinity of GlpE for both thiosulfate and cyanide suggests that these compounds are not the physiological substrates. Thioredoxin 1 or related dithiol proteins could instead be the physiological sulfur-acceptor substrate. Possible association with the metabolism of glycerol-phosphate remains to be elucidated.

Sulfite reductase, alpha subunit, flavoprotein; Component of the sulfite reductase complex that catalyzes the 6-electron reduction of sulfite to sulfide. This is one of several activities required for the biosynthesis of L-cysteine from sulfate. The flavoprotein component catalyzes the electron flow from NADPH -> FAD -> FMN to the hemoprotein component; In the N-terminal section; belongs to the flavodoxin family.

Cystathionine gamma-synthase, PLP-dependent; Catalyzes the formation of L-cystathionine from O-succinyl-L- homoserine (OSHS) and L-cysteine, via a gamma-replacement reaction. In the absence of thiol, catalyzes gamma-elimination to form 2- oxobutanoate, succinate and ammonia.

2,3-dihydro-2,3-dihydroxybenzoate dehydrogenase; Involved in the biosynthesis of the siderophore enterobactin (enterochelin), which is a macrocyclic trimeric lactone of N-(2,3- dihydroxybenzoyl)-serine. Catalyzes the reversible NAD-dependent oxidation of the C3-hydroxyl group of 2,3-dihydro-2,3-dihydroxybenzoate (2,3-diDHB), producing the transient intermediate 2-hydroxy-3-oxo-4,6- cyclohexadiene-1-carboxylate, which undergoes rapid aromatization to the final product, 2,3-dihydroxybenzoate (2,3-DHB). Only the compounds with a C3-hydroxyl group such as methyl 2,3-dihydro-2,3- dihydroxyb [...]

Isochorismatase; Involved in the biosynthesis of the siderophore enterobactin (enterochelin), which is a macrocyclic trimeric lactone of N-(2,3- dihydroxybenzoyl)-serine. The serine trilactone serves as a scaffolding for the three catechol functionalities that provide hexadentate coordination for the tightly ligated iron(2+) atoms. EntB is a bifunctional protein that serves as an isochorismate lyase and an aryl carrier protein (ArCP). Catalyzes the conversion of isochorismate to 2,3-dihydro-2,3-dihydroxybenzoate (2,3-diDHB), the precursor of 2,3- dihydroxybenzoate (DHB). In the enterob [...]

2,3-dihydro-2,3-dihydroxybenzoate dehydrogenase; Involved in the biosynthesis of the siderophore enterobactin (enterochelin), which is a macrocyclic trimeric lactone of N-(2,3- dihydroxybenzoyl)-serine. Catalyzes the reversible NAD-dependent oxidation of the C3-hydroxyl group of 2,3-dihydro-2,3-dihydroxybenzoate (2,3-diDHB), producing the transient intermediate 2-hydroxy-3-oxo-4,6- cyclohexadiene-1-carboxylate, which undergoes rapid aromatization to the final product, 2,3-dihydroxybenzoate (2,3-DHB). Only the compounds with a C3-hydroxyl group such as methyl 2,3-dihydro-2,3- dihydroxyb [...]

Isochorismate synthase 1; Involved in the biosynthesis of the siderophore enterobactin (macrocyclic trimeric lactone of N-(2,3-dihydroxybenzoyl)-serine). Catalyzes the reversible conversion of chorismate to isochorismate.

2,3-dihydro-2,3-dihydroxybenzoate dehydrogenase; Involved in the biosynthesis of the siderophore enterobactin (enterochelin), which is a macrocyclic trimeric lactone of N-(2,3- dihydroxybenzoyl)-serine. Catalyzes the reversible NAD-dependent oxidation of the C3-hydroxyl group of 2,3-dihydro-2,3-dihydroxybenzoate (2,3-diDHB), producing the transient intermediate 2-hydroxy-3-oxo-4,6- cyclohexadiene-1-carboxylate, which undergoes rapid aromatization to the final product, 2,3-dihydroxybenzoate (2,3-DHB). Only the compounds with a C3-hydroxyl group such as methyl 2,3-dihydro-2,3- dihydroxyb [...]

Phosphopantetheinyltransferase component of enterobactin synthase multienzyme complex; Involved in the biosynthesis of the siderophore enterobactin (enterochelin), which is a macrocyclic trimeric lactone of N-(2,3- dihydroxybenzoyl)-serine. The serine trilactone serves as a scaffolding for the three catechol functionalities that provide hexadentate coordination for the tightly ligated iron(2+) atoms. Plays an essential role in the assembly of the enterobactin by catalyzing the transfer of the 4'-phosphopantetheine (Ppant) moiety from coenzyme A to the apo- domains of both EntB (ArCP do [...]

2,3-dihydro-2,3-dihydroxybenzoate dehydrogenase; Involved in the biosynthesis of the siderophore enterobactin (enterochelin), which is a macrocyclic trimeric lactone of N-(2,3- dihydroxybenzoyl)-serine. Catalyzes the reversible NAD-dependent oxidation of the C3-hydroxyl group of 2,3-dihydro-2,3-dihydroxybenzoate (2,3-diDHB), producing the transient intermediate 2-hydroxy-3-oxo-4,6- cyclohexadiene-1-carboxylate, which undergoes rapid aromatization to the final product, 2,3-dihydroxybenzoate (2,3-DHB). Only the compounds with a C3-hydroxyl group such as methyl 2,3-dihydro-2,3- dihydroxyb [...]

2,3-dihydroxybenzoate-AMP ligase component of enterobactin synthase multienzyme complex; Involved in the biosynthesis of the siderophore enterobactin (enterochelin), which is a macrocyclic trimeric lactone of N-(2,3- dihydroxybenzoyl)-serine. The serine trilactone serves as a scaffolding for the three catechol functionalities that provide hexadentate coordination for the tightly ligated iron(2+) atoms. EntE proccesses via a two-step adenylation-ligation reaction (bi-uni-uni-bi ping-pong mechanism). First, it catalyzes the activation of the carboxylate group of 2,3-dihydroxy-benzoate (D [...]

2,3-dihydro-2,3-dihydroxybenzoate dehydrogenase; Involved in the biosynthesis of the siderophore enterobactin (enterochelin), which is a macrocyclic trimeric lactone of N-(2,3- dihydroxybenzoyl)-serine. Catalyzes the reversible NAD-dependent oxidation of the C3-hydroxyl group of 2,3-dihydro-2,3-dihydroxybenzoate (2,3-diDHB), producing the transient intermediate 2-hydroxy-3-oxo-4,6- cyclohexadiene-1-carboxylate, which undergoes rapid aromatization to the final product, 2,3-dihydroxybenzoate (2,3-DHB). Only the compounds with a C3-hydroxyl group such as methyl 2,3-dihydro-2,3- dihydroxyb [...]

Enterobactin synthase multienzyme complex component, ATP-dependent; Activates the carboxylate group of L-serine via ATP-dependent PPi exchange reactions to the aminoacyladenylate, preparing that molecule for the final stages of enterobactin synthesis. Holo-EntF acts as the catalyst for the formation of the three amide and three ester bonds present in the cyclic (2,3-dihydroxybenzoyl)serine trimer enterobactin, using seryladenylate and acyl-holo-EntB (acylated with 2,3-dihydroxybenzoate by EntE).

2,3-dihydro-2,3-dihydroxybenzoate dehydrogenase; Involved in the biosynthesis of the siderophore enterobactin (enterochelin), which is a macrocyclic trimeric lactone of N-(2,3- dihydroxybenzoyl)-serine. Catalyzes the reversible NAD-dependent oxidation of the C3-hydroxyl group of 2,3-dihydro-2,3-dihydroxybenzoate (2,3-diDHB), producing the transient intermediate 2-hydroxy-3-oxo-4,6- cyclohexadiene-1-carboxylate, which undergoes rapid aromatization to the final product, 2,3-dihydroxybenzoate (2,3-DHB). Only the compounds with a C3-hydroxyl group such as methyl 2,3-dihydro-2,3- dihydroxyb [...]

Enterobactin exporter, iron-regulated; Component of an export pathway for enterobactin. Overexpression reduces intracellular arabinose concentrations.

2,3-dihydro-2,3-dihydroxybenzoate dehydrogenase; Involved in the biosynthesis of the siderophore enterobactin (enterochelin), which is a macrocyclic trimeric lactone of N-(2,3- dihydroxybenzoyl)-serine. Catalyzes the reversible NAD-dependent oxidation of the C3-hydroxyl group of 2,3-dihydro-2,3-dihydroxybenzoate (2,3-diDHB), producing the transient intermediate 2-hydroxy-3-oxo-4,6- cyclohexadiene-1-carboxylate, which undergoes rapid aromatization to the final product, 2,3-dihydroxybenzoate (2,3-DHB). Only the compounds with a C3-hydroxyl group such as methyl 2,3-dihydro-2,3- dihydroxyb [...]

Ferrienterobactin outer membrane transporter; This protein is involved in the initial step of iron uptake by binding ferrienterobactin (Fe-ENT), an iron chelatin siderophore that allows E.coli to extract iron from the environment. FepA also acts as a receptor for colicins B and D.

Isochorismatase; Involved in the biosynthesis of the siderophore enterobactin (enterochelin), which is a macrocyclic trimeric lactone of N-(2,3- dihydroxybenzoyl)-serine. The serine trilactone serves as a scaffolding for the three catechol functionalities that provide hexadentate coordination for the tightly ligated iron(2+) atoms. EntB is a bifunctional protein that serves as an isochorismate lyase and an aryl carrier protein (ArCP). Catalyzes the conversion of isochorismate to 2,3-dihydro-2,3-dihydroxybenzoate (2,3-diDHB), the precursor of 2,3- dihydroxybenzoate (DHB). In the enterob [...]

2,3-dihydro-2,3-dihydroxybenzoate dehydrogenase; Involved in the biosynthesis of the siderophore enterobactin (enterochelin), which is a macrocyclic trimeric lactone of N-(2,3- dihydroxybenzoyl)-serine. Catalyzes the reversible NAD-dependent oxidation of the C3-hydroxyl group of 2,3-dihydro-2,3-dihydroxybenzoate (2,3-diDHB), producing the transient intermediate 2-hydroxy-3-oxo-4,6- cyclohexadiene-1-carboxylate, which undergoes rapid aromatization to the final product, 2,3-dihydroxybenzoate (2,3-DHB). Only the compounds with a C3-hydroxyl group such as methyl 2,3-dihydro-2,3- dihydroxyb [...]

Isochorismatase; Involved in the biosynthesis of the siderophore enterobactin (enterochelin), which is a macrocyclic trimeric lactone of N-(2,3- dihydroxybenzoyl)-serine. The serine trilactone serves as a scaffolding for the three catechol functionalities that provide hexadentate coordination for the tightly ligated iron(2+) atoms. EntB is a bifunctional protein that serves as an isochorismate lyase and an aryl carrier protein (ArCP). Catalyzes the conversion of isochorismate to 2,3-dihydro-2,3-dihydroxybenzoate (2,3-diDHB), the precursor of 2,3- dihydroxybenzoate (DHB). In the enterob [...]

Isochorismate synthase 1; Involved in the biosynthesis of the siderophore enterobactin (macrocyclic trimeric lactone of N-(2,3-dihydroxybenzoyl)-serine). Catalyzes the reversible conversion of chorismate to isochorismate.

Isochorismatase; Involved in the biosynthesis of the siderophore enterobactin (enterochelin), which is a macrocyclic trimeric lactone of N-(2,3- dihydroxybenzoyl)-serine. The serine trilactone serves as a scaffolding for the three catechol functionalities that provide hexadentate coordination for the tightly ligated iron(2+) atoms. EntB is a bifunctional protein that serves as an isochorismate lyase and an aryl carrier protein (ArCP). Catalyzes the conversion of isochorismate to 2,3-dihydro-2,3-dihydroxybenzoate (2,3-diDHB), the precursor of 2,3- dihydroxybenzoate (DHB). In the enterob [...]

Phosphopantetheinyltransferase component of enterobactin synthase multienzyme complex; Involved in the biosynthesis of the siderophore enterobactin (enterochelin), which is a macrocyclic trimeric lactone of N-(2,3- dihydroxybenzoyl)-serine. The serine trilactone serves as a scaffolding for the three catechol functionalities that provide hexadentate coordination for the tightly ligated iron(2+) atoms. Plays an essential role in the assembly of the enterobactin by catalyzing the transfer of the 4'-phosphopantetheine (Ppant) moiety from coenzyme A to the apo- domains of both EntB (ArCP do [...]