Page last updated: 2024-10-24

cysteine biosynthetic process

Definition

Target type: biologicalprocess

The chemical reactions and pathways resulting in the formation of cysteine, 2-amino-3-mercaptopropanoic acid. [GOC:go_curators]

Cysteine biosynthesis is a fundamental metabolic process that produces the sulfur-containing amino acid cysteine. This amino acid plays crucial roles in various cellular functions, including protein synthesis, redox homeostasis, and detoxification. The biosynthesis of cysteine involves a series of enzymatic reactions, starting with the conversion of serine to O-acetylserine by the enzyme serine acetyltransferase. O-acetylserine is then converted to cysteine by the enzyme cysteine synthase, which incorporates sulfide into the molecule. This sulfide is derived from the reduction of sulfate, a process that occurs in the cytoplasm. The cysteine biosynthesis pathway is highly regulated, with feedback mechanisms ensuring that the synthesis of cysteine is tightly coupled to the cell's needs. The regulation of this pathway is critical for maintaining cellular homeostasis and preventing the accumulation of toxic intermediates. In humans, cysteine biosynthesis occurs primarily in the liver. Deficiencies in cysteine biosynthesis can lead to a variety of health problems, including neurological disorders, developmental delays, and immune dysfunction.'
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Proteins (3)

ProteinDefinitionTaxonomy
Cystathionine beta-synthaseA cystathionine beta-synthase that is encoded in the genome of human. [PRO:DNx, UniProtKB:P35520]Homo sapiens (human)
Cystathionine gamma-lyaseA cystathionine gamma-lyase that is encoded in the genome of human. [PRO:DNx, UniProtKB:P32929]Homo sapiens (human)
Glutathione hydrolase 1 proenzymeA glutathione hydrolase 1 proenzyme that is encoded in the genome of human. [PRO:CNA, UniProtKB:P19440]Homo sapiens (human)

Compounds (19)

CompoundDefinitionClassesRoles
aminooxyacetic acid(aminooxy)acetic acid : A member of the class of hydroxylamines that is acetic acid substituted at postion 2 by an aminooxy group. It is a compound which inhibits aminobutyrate aminotransferase activity in vivo, resulting in increased levels of gamma-aminobutyric acid in tissues.

Aminooxyacetic Acid: A compound that inhibits aminobutyrate aminotransferase activity in vivo, thereby raising the level of gamma-aminobutyric acid in tissues.
amino acid;
hydroxylamines;
monocarboxylic acid
anticonvulsant;
EC 2.6.1.19 (4-aminobutyrate--2-oxoglutarate transaminase) inhibitor;
EC 4.2.1.22 (cystathionine beta-synthase) inhibitor;
nootropic agent
salicylic acidScalp: The outer covering of the calvaria. It is composed of several layers: SKIN; subcutaneous connective tissue; the occipitofrontal muscle which includes the tendinous galea aponeurotica; loose connective tissue; and the pericranium (the PERIOSTEUM of the SKULL).monohydroxybenzoic acidalgal metabolite;
antifungal agent;
antiinfective agent;
EC 1.11.1.11 (L-ascorbate peroxidase) inhibitor;
keratolytic drug;
plant hormone;
plant metabolite
aspirinacetylsalicylate : A benzoate that is the conjugate base of acetylsalicylic acid, arising from deprotonation of the carboxy group.

acetylsalicylic acid : A member of the class of benzoic acids that is salicylic acid in which the hydrogen that is attached to the phenolic hydroxy group has been replaced by an acetoxy group. A non-steroidal anti-inflammatory drug with cyclooxygenase inhibitor activity.

Aspirin: The prototypical analgesic used in the treatment of mild to moderate pain. It has anti-inflammatory and antipyretic properties and acts as an inhibitor of cyclooxygenase which results in the inhibition of the biosynthesis of prostaglandins. Aspirin also inhibits platelet aggregation and is used in the prevention of arterial and venous thrombosis. (From Martindale, The Extra Pharmacopoeia, 30th ed, p5)
benzoic acids;
phenyl acetates;
salicylates
anticoagulant;
antipyretic;
cyclooxygenase 1 inhibitor;
cyclooxygenase 2 inhibitor;
drug allergen;
EC 1.1.1.188 (prostaglandin-F synthase) inhibitor;
geroprotector;
non-narcotic analgesic;
non-steroidal anti-inflammatory drug;
plant activator;
platelet aggregation inhibitor;
prostaglandin antagonist;
teratogenic agent
aurintricarboxylic acidaurintricarboxylic acid : A member of the class of quinomethanes that is 3-methylidene-6-oxocyclohexa-1,4-diene-1-carboxylic acid in which the methylidene hydrogens are replaced by 4-carboxy-3-hydroxyphenyl groups. The trisodium salt is the biological stain 'chrome violet CG' while the triammonium salt is 'aluminon'.

Aurintricarboxylic Acid: A dye which inhibits protein biosynthesis at the initial stages. The ammonium salt (aluminon) is a reagent for the colorimetric estimation of aluminum in water, foods, and tissues.
monohydroxybenzoic acid;
quinomethanes;
tricarboxylic acid
fluorochrome;
histological dye;
insulin-like growth factor receptor 1 antagonist
hypericin
mesalaminemesalamine : A monohydroxybenzoic acid that is salicylic acid substituted by an amino group at the 5-position.

Mesalamine: An anti-inflammatory agent, structurally related to the SALICYLATES, which is active in INFLAMMATORY BOWEL DISEASE. It is considered to be the active moiety of SULPHASALAZINE. (From Martindale, The Extra Pharmacopoeia, 30th ed)
amino acid;
aromatic amine;
monocarboxylic acid;
monohydroxybenzoic acid;
phenols
non-steroidal anti-inflammatory drug
penicillaminepenicillamine : An alpha-amino acid having the structure of valine substituted at the beta position with a sulfanyl group.

Penicillamine: 3-Mercapto-D-valine. The most characteristic degradation product of the penicillin antibiotics. It is used as an antirheumatic and as a chelating agent in Wilson's disease.
non-proteinogenic alpha-amino acid;
penicillamine
antirheumatic drug;
chelator;
copper chelator;
drug allergen
nitroxolinenitroxoline : A monohydroxyquinoline in which the hydroxy group is positioned at C-8 with a nitro group trans to it at C-5.

nitroxoline: structure in Merck Index, 9th ed, #6475; RN given refers to parent cpd
C-nitro compound;
monohydroxyquinoline
antifungal agent;
antiinfective agent;
antimicrobial agent;
renal agent
olsalazineolsalazine : An azobenzene that consists of two molecules of 4-aminosalicylic acid joined by an azo linkage. A prodrug for mesalazine, an anti-inflammatory drug, it is used (as the disodium salt) in the treatment of inflammatory bowel disease.

olsalazine: cpd with 2 salicylate molecules linked together by an azo bond
azobenzenes;
dicarboxylic acid
non-steroidal anti-inflammatory drug;
prodrug
methyldopaalpha-methyl-L-dopa : A derivative of L-tyrosine having a methyl group at the alpha-position and an additional hydroxy group at the 3-position on the phenyl ring.

Methyldopa: An alpha-2 adrenergic agonist that has both central and peripheral nervous system effects. Its primary clinical use is as an antihypertensive agent.
L-tyrosine derivative;
non-proteinogenic L-alpha-amino acid
alpha-adrenergic agonist;
antihypertensive agent;
hapten;
peripheral nervous system drug;
sympatholytic agent
6-amino-7-chloro-5,8-dioxoquinoline6-amino-7-chloro-5,8-dioxoquinoline: quinone structure important in this cpd; structure
kalafunginkalafungin: nanaomycin D from Streptomyces rosa & is enantiomer of kalafungin; RN given refers to (3aR-(3aalpha,5alpha,11balpha))-isomer; see also nanaomycin C; structure of kalafungin in first source; structure of nanaomycin in second source
nsc228155
agathisflavoneagathisflavone : A biflavonoid that is obtained by oxidative coupling of two molecules of apigenin resulting in a bond between positions C-6 and C-8 of the two chromene rings.

agathisflavone: bis-apigenin coupled at 6 and 8 positions; isolated from the plant Canarium manii; has hepatoprotective activity against carbon tetrachloride-induced hepatotoxicity
biaryl;
biflavonoid;
hydroxyflavone
antineoplastic agent;
antiviral agent;
hepatoprotective agent;
metabolite
cupressuflavonecupressuflavone : A biflavonoid that is obtained by oxidative coupling of two molecules of apigenin resulting in a bond between positions C-8 of the two chromene rings respectively. Isolated from Cupressus sempervirens and Juniperus occidentalis, it exhibits free radical scavenging and antielastase activities.

cupressuflavone: from Cupressus macrocarpa; structure in first source
biflavonoid;
hydroxyflavone;
ring assembly
EC 3.4.21.37 (leukocyte elastase) inhibitor;
metabolite;
radical scavenger
myricetin7-hydroxyflavonol;
hexahydroxyflavone
antineoplastic agent;
antioxidant;
cyclooxygenase 1 inhibitor;
food component;
geroprotector;
hypoglycemic agent;
plant metabolite
podocarpusflavone apodocarpusflavone A: isolated from Podocarpus imbricatusflavonoid oligomer
rubrolide arubrolide A: from Synoicum prunum; structure in first source
aminoethoxyvinylglycineaminoethoxyvinylglycine: RN given for (S-(E))-isomer