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Record Information
Version3.6
Creation Date2006-05-22 15:12:47 UTC
Update Date2013-05-13 20:33:20 UTC
HMDB IDHMDB03288
Secondary Accession NumbersNone
Metabolite Identification
Common NameSelenocysteine
DescriptionSelenocysteine is an amino acid that is present in several enzymes (for example glutathione peroxidases, tetraiodothyronine 5' deiodinases, thioredoxin reductases, formate dehydrogenases, glycine reductases and some hydrogenases). Selenocysteine has a structure similar to cysteine, but with an atom of selenium taking the place of the usual sulfur. Proteins that include a selenocysteine residue are called selenoproteins (Wikipedia). Selenocysteine is a naturally occurring amino acid in both eukaryotic and prokaryotic organisms. It is found in tRNAs and in the catalytic site of some enzymes. The genes for glutathione peroxidase and formate dehydrogenase contain the TGA codon, which codes for this amino acid (Pubchem).
Structure
Thumb
Synonyms
  1. (2R)-2-amino-3-selanylpropanoate
  2. (2R)-2-amino-3-selanylpropanoic acid
  3. 3-Seleno-alanine
  4. 3-Selenoalanine
  5. 3-Selenyl-L-Alanine
  6. L-Selenocystein
  7. L-Selenocysteine
  8. L-Selenozystein
Chemical FormulaC3H7NO2Se
Average Molecular Weight168.05
Monoisotopic Molecular Weight168.964200301
IUPAC Name(2R)-2-amino-3-selanylpropanoic acid
Traditional IUPAC Nameselenocysteine
CAS Registry Number3614-08-2
SMILES
N[C@@H](C[SeH])C(O)=O
InChI Identifier
InChI=1S/C3H7NO2Se/c4-2(1-7)3(5)6/h2,7H,1,4H2,(H,5,6)/t2-/m0/s1
InChI KeyZKZBPNGNEQAJSX-REOHCLBHSA-N
Chemical Taxonomy
KingdomOrganic Compounds
Super ClassAmino Acids, Peptides, and Analogues
ClassAmino Acids and Derivatives
Sub ClassAlpha Amino Acids and Derivatives
Other Descriptors
  • Aliphatic Acyclic Compounds
  • alpha-amino acid(ChEBI)
  • selenocysteines(ChEBI)
Substituents
  • Carboxylic Acid
  • Primary Aliphatic Amine (Alkylamine)
  • Selenol
Direct ParentAlpha Amino Acids and Derivatives
Ontology
StatusExpected and Not Quantified
Origin
  • Endogenous
Biofunction
  • Protein synthesis, amino acid biosynthesis
ApplicationNot Available
Cellular locations
  • Cytoplasm
Physical Properties
StateSolid
Experimental Properties
PropertyValueReference
Melting PointNot AvailableNot Available
Boiling PointNot AvailableNot Available
Water SolubilityNot AvailableNot Available
LogPNot AvailableNot Available
Predicted Properties
PropertyValueSource
water solubility325 g/LALOGPS
logP-3.2ALOGPS
logP-4.1ChemAxon
logS0.29ALOGPS
pKa (strongest acidic)1.27ChemAxon
pKa (strongest basic)8.42ChemAxon
physiological charge0ChemAxon
hydrogen acceptor count3ChemAxon
hydrogen donor count2ChemAxon
polar surface area63.32ChemAxon
rotatable bond count2ChemAxon
refractivity33.45ChemAxon
polarizability10.7ChemAxon
Spectra
SpectraNot Available
Biological Properties
Cellular Locations
  • Cytoplasm
Biofluid LocationsNot Available
Tissue Location
  • Fibroblasts
  • Kidney
  • Testes
  • Thyroid Gland
Pathways
NameSMPDB LinkKEGG Link
Selenoamino Acid MetabolismSMP00029map00450
Normal Concentrations
Not Available
Abnormal Concentrations
Not Available
Associated Disorders and Diseases
Disease ReferencesNone
Associated OMIM IDsNone
DrugBank IDDB02345
DrugBank Metabolite IDNot Available
Phenol Explorer Compound IDNot Available
Phenol Explorer Metabolite IDNot Available
FoodDB IDFDB002262
KNApSAcK IDC00034230
Chemspider ID23436
KEGG Compound IDC05688
BioCyc IDL-SELENOCYSTEINE
BiGG ID46290
Wikipedia LinkSelenocysteine
NuGOwiki LinkHMDB03288
Metagene LinkHMDB03288
METLIN ID3292
PubChem Compound25076
PDB IDCSE
ChEBI ID16633
References
Synthesis ReferenceNot Available
Material Safety Data Sheet (MSDS)Not Available
General References
  1. Chu FF, Esworthy RS, Doroshow JH, Doan K, Liu XF: Expression of plasma glutathione peroxidase in human liver in addition to kidney, heart, lung, and breast in humans and rodents. Blood. 1992 Jun 15;79(12):3233-8. Pubmed: 1339300
  2. Mostert V, Wolff S, Dreher I, Kohrle J, Abel J: Identification of an element within the promoter of human selenoprotein P responsive to transforming growth factor-beta. Eur J Biochem. 2001 Dec;268(23):6176-81. Pubmed: 11733012
  3. Zimmermann MB, Kohrle J: The impact of iron and selenium deficiencies on iodine and thyroid metabolism: biochemistry and relevance to public health. Thyroid. 2002 Oct;12(10):867-78. Pubmed: 12487769
  4. Sun QA, Su D, Novoselov SV, Carlson BA, Hatfield DL, Gladyshev VN: Reaction mechanism and regulation of mammalian thioredoxin/glutathione reductase. Biochemistry. 2005 Nov 8;44(44):14528-37. Pubmed: 16262253
  5. Blotcky AJ, Ebrahim A, Rack EP: Determination of selenium metabolites in biological fluids using instrumental and molecular neutron activation analysis. Anal Chem. 1988 Dec 15;60(24):2734-7. Pubmed: 3245598
  6. Utomo A, Jiang X, Furuta S, Yun J, Levin DS, Wang YC, Desai KV, Green JE, Chen PL, Lee WH: Identification of a novel putative non-selenocysteine containing phospholipid hydroperoxide glutathione peroxidase (NPGPx) essential for alleviating oxidative stress generated from polyunsaturated fatty acids in breast cancer cells. J Biol Chem. 2004 Oct 15;279(42):43522-9. Epub 2004 Aug 4. Pubmed: 15294905
  7. Rooseboom M, Vermeulen NP, Andreadou I, Commandeur JN: Evaluation of the kinetics of beta-elimination reactions of selenocysteine Se-conjugates in human renal cytosol: possible implications for the use as kidney selective prodrugs. J Pharmacol Exp Ther. 2000 Aug;294(2):762-9. Pubmed: 10900258
  8. Zinoni F, Birkmann A, Stadtman TC, Bock A: Nucleotide sequence and expression of the selenocysteine-containing polypeptide of formate dehydrogenase (formate-hydrogen-lyase-linked) from Escherichia coli. Proc Natl Acad Sci U S A. 1986 Jul;83(13):4650-4. Pubmed: 2941757

Enzymes

General function:
Involved in nucleoside diphosphate kinase activity
Specific function:
Major role in the synthesis of nucleoside triphosphates other than ATP. Possesses nucleoside-diphosphate kinase, serine/threonine-specific protein kinase, geranyl and farnesyl pyrophosphate kinase, histidine protein kinase and 3'-5' exonuclease activities. Involved in cell proliferation, differentiation and development, signal transduction, G protein-coupled receptor endocytosis, and gene expression. Required for neural development including neural patterning and cell fate determination.
Gene Name:
NME1
Uniprot ID:
P15531
Molecular weight:
17148.635
References
  1. Overington JP, Al-Lazikani B, Hopkins AL: How many drug targets are there? Nat Rev Drug Discov. 2006 Dec;5(12):993-6. Pubmed: 17139284
  2. Imming P, Sinning C, Meyer A: Drugs, their targets and the nature and number of drug targets. Nat Rev Drug Discov. 2006 Oct;5(10):821-34. Pubmed: 17016423
  3. Berman HM, Westbrook J, Feng Z, Gilliland G, Bhat TN, Weissig H, Shindyalov IN, Bourne PE: The Protein Data Bank. Nucleic Acids Res. 2000 Jan 1;28(1):235-42. Pubmed: 10592235
General function:
Involved in oxidoreductase activity
Specific function:
Isoform 1 may possess glutaredoxin activity as well as thioredoxin reductase activity and induces actin and tubulin polymerization, leading to formation of cell membrane protrusions. Isoform 4 enhances the transcriptional activity of estrogen receptors alpha and beta while isoform 5 enhances the transcriptional activity of the beta receptor only. Isoform 5 also mediates cell death induced by a combination of interferon-beta and retinoic acid.
Gene Name:
TXNRD1
Uniprot ID:
Q16881
Molecular weight:
70905.58
General function:
Involved in oxidoreductase activity
Specific function:
Maintains thioredoxin in a reduced state. Implicated in the defenses against oxidative stress. May play a role in redox-regulated cell signaling.
Gene Name:
TXNRD2
Uniprot ID:
Q9NNW7
Molecular weight:
56506.275
General function:
Involved in pyridoxal phosphate binding
Specific function:
Catalyzes the last step in the trans-sulfuration pathway from methionine to cysteine. Has broad substrate specificity. Converts cystathionine to cysteine, ammonia and 2-oxobutanoate. Converts two cysteine molecules to lanthionine and hydrogen sulfide. Can also accept homocysteine as substrate. Specificity depends on the levels of the endogenous substrates. Generates the endogenous signaling molecule hydrogen sulfide (H2S), and so contributes to the regulation of blood pressure. Acts as a cysteine-protein sulfhydrase by mediating sulfhydration of target proteins: sulfhydration consists of converting -SH groups into -SSH on specific cysteine residues of target proteins such as GAPDH, PTPN1 and NF-kappa-B subunit RELA, thereby regulating their function.
Gene Name:
CTH
Uniprot ID:
P32929
Molecular weight:
41259.91
Reactions
Selenocystathionine + Water → Selenocysteine + Ammonia + 2-Ketobutyric aciddetails
General function:
Involved in catalytic activity
Specific function:
Synthesizes selenophosphate from selenide and ATP.
Gene Name:
SEPHS2
Uniprot ID:
Q99611
Molecular weight:
47304.695
General function:
Involved in glutathione peroxidase activity
Specific function:
Protects the hemoglobin in erythrocytes from oxidative breakdown.
Gene Name:
GPX1
Uniprot ID:
P07203
Molecular weight:
22087.94
General function:
Involved in glutathione peroxidase activity
Specific function:
Protects cells against membrane lipid peroxidation and cell death. Required for normal sperm development and male fertility. Could play a major role in protecting mammals from the toxicity of ingested lipid hydroperoxides. Essential for embryonic development. Protects from radiation and oxidative damage (By similarity).
Gene Name:
GPX4
Uniprot ID:
P36969
Molecular weight:
25046.57
General function:
Involved in glutathione peroxidase activity
Specific function:
Protects cells and enzymes from oxidative damage, by catalyzing the reduction of hydrogen peroxide, lipid peroxides and organic hydroperoxide, by glutathione.
Gene Name:
GPX3
Uniprot ID:
P22352
Molecular weight:
25552.185
General function:
Involved in glutathione peroxidase activity
Specific function:
Could play a major role in protecting mammals from the toxicity of ingested organic hydroperoxides. Tert-butyl hydroperoxide, cumene hydroperoxide and linoleic acid hydroperoxide but not phosphatidycholine hydroperoxide, can act as acceptors.
Gene Name:
GPX2
Uniprot ID:
P18283
Molecular weight:
21953.835
General function:
Involved in thyroxine 5'-deiodinase activity
Specific function:
Responsible for the deiodination of T4 (3,5,3',5'-tetraiodothyronine) into T3 (3,5,3'-triiodothyronine) and of T3 into T2 (3,3'-diiodothyronine). Plays a role in providing a source of plasma T3 by deiodination of T4 in peripheral tissues such as liver and kidney.
Gene Name:
DIO1
Uniprot ID:
P49895
Molecular weight:
28924.21
General function:
Involved in thyroxine 5'-deiodinase activity
Specific function:
Responsible for the deiodination of T4 (3,5,3',5'-tetraiodothyronine) into T3 (3,5,3'-triiodothyronine). Essential for providing the brain with appropriate levels of T3 during the critical period of development.
Gene Name:
DIO2
Uniprot ID:
Q92813
Molecular weight:
30551.48
General function:
Involved in metabolic process
Specific function:
Catalyzes the decomposition of L-selenocysteine to L-alanine and elemental selenium (By similarity).
Gene Name:
SCLY
Uniprot ID:
Q96I15
Molecular weight:
48793.15
Reactions
Selenocysteine + reduced acceptor → Hydrogen selenide + L-Alanine + acceptordetails
Selenocysteine + Reduced acceptor → Hydrogen selenide + L-Alanine + Acceptordetails
General function:
Involved in oxidoreductase activity
Specific function:
Displays thioredoxin reductase, glutaredoxin and glutathione reductase activities. Catalyzes disulfide bond isomerization. Promotes disulfide bond formation between GPX4 and various sperm proteins and may play a role in sperm maturation by promoting formation of sperm structural components (By similarity).
Gene Name:
TXNRD3
Uniprot ID:
Q86VQ6
Molecular weight:
66600.92
General function:
Involved in phosphotransferase activity, for other substituted phosphate groups
Specific function:
Catalyzes phosphatidylethanolamine biosynthesis from CDP-ethanolamine. It thereby plays a central role in the formation and maintenance of vesicular membranes. Involved in the formation of phosphatidylethanolamine via 'Kennedy' pathway.
Gene Name:
EPT1
Uniprot ID:
Q9C0D9
Molecular weight:
45228.42
General function:
Involved in catalytic activity
Specific function:
Converts O-phosphoseryl-tRNA(Sec) to selenocysteinyl-tRNA(Sec) required for selenoprotein biosynthesis.
Gene Name:
SEPSECS
Uniprot ID:
Q9HD40
Molecular weight:
55725.69
General function:
Involved in oxidoreductase activity
Specific function:
Can reduce the dialdehyde protein-binding form of aflatoxin B1 (AFB1) to the non-binding AFB1 dialcohol. May be involved in protection of liver against the toxic and carcinogenic effects of AFB1, a potent hepatocarcinogen
Gene Name:
AKR7L
Uniprot ID:
Q8NHP1
Molecular weight:
36963.5
General function:
Involved in peptide-methionine-(S)-S-oxide reductase activity
Specific function:
Not Available
Gene Name:
MSRB1
Uniprot ID:
Q9NZV6
Molecular weight:
12760.095
General function:
Involved in selenium binding
Specific function:
Might be responsible for some of the extracellular antioxidant defense properties of selenium or might be involved in the transport of selenium. May supply selenium to tissues such as brain and testis
Gene Name:
SEPP1
Uniprot ID:
P49908
Molecular weight:
43173.4
General function:
Involved in selenium binding
Specific function:
May be involved in redox reactions associated with the formation of disulfide bonds. May contribute to the quality control of protein folding in the endoplasmic reticulum
Gene Name:
SEP15
Uniprot ID:
O60613
Molecular weight:
17790.2
General function:
Involved in protein binding
Specific function:
Not Available
Gene Name:
SEPN1
Uniprot ID:
Q9NZV5
Molecular weight:
65826.1
General function:
Involved in selenium binding
Specific function:
May be involved in a redox-related process. May play a role in the myopathies of selenium deficiency
Gene Name:
SEPW1
Uniprot ID:
P63302
Molecular weight:
9447.9
General function:
Involved in selenium binding
Specific function:
Involved in the degradation process of misfolded endoplasmic reticulum (ER) luminal proteins. Participates in the transfer of misfolded proteins from the ER to the cytosol, where they are destroyed by the proteasome in a ubiquitin-dependent manner. Probably acts by serving as a linker between DERL1, which mediates the retrotranslocation of misfolded proteins into the cytosol, and the ATPase complex VCP, which mediates the translocation and ubiquitination
Gene Name:
SELS
Uniprot ID:
Q9BQE4
Molecular weight:
21162.8
General function:
Involved in response to oxidative stress
Specific function:
Not Available
Gene Name:
SELK
Uniprot ID:
Q9Y6D0
Molecular weight:
10644.9
General function:
Not Available
Specific function:
May function as a thiol-disulfide oxidoreductase that participates in disulfide bond formation
Gene Name:
SELM
Uniprot ID:
Q8WWX9
Molecular weight:
16231.5
General function:
Involved in selenium binding
Specific function:
Not Available
Gene Name:
SELT
Uniprot ID:
P62341
Molecular weight:
22324.0