Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
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Chemical compound
Selenocysteine (symbol Sec or U,[4] in older publications also as Se-Cys)[5] is the 21st proteinogenic amino acid. Selenoproteins contain selenocysteine residues. Selenocysteine is an analogue of the more common cysteine with selenium in place of the sulfur.
Selenocysteine is present in several enzymes (for example glutathione peroxidases, tetraiodothyronine 5′ deiodinases, thioredoxin reductases, formate dehydrogenases, glycine reductases, selenophosphate synthetase 2, methionine-R-sulfoxide reductase B1 (SEPX1), and some hydrogenases). It occurs in all three domains of life, including important enzymes (listed above) present in humans.[6]
Selenocysteine was discovered in 1974[7] by biochemist Thressa Stadtman at the National Institutes of Health.[8]
^Merck Index, 12th Edition, 8584
^Huber RE, Criddle RS (1967-10-01). "Comparison of the chemical properties of selenocysteine and selenocystine with their sulfur analogs". Archives of Biochemistry and Biophysics. 122 (1): 164–173. doi:10.1016/0003-9861(67)90136-1. ISSN 0003-9861. PMID 6076213.
^Thapa B, Schlegel HB (2016-11-10). "Theoretical Calculation of p K a 's of Selenols in Aqueous Solution Using an Implicit Solvation Model and Explicit Water Molecules". The Journal of Physical Chemistry A. 120 (44): 8916–8922. Bibcode:2016JPCA..120.8916T. doi:10.1021/acs.jpca.6b09520. ISSN 1089-5639. PMID 27748600.
^"Nomenclature and Symbolism for Amino Acids and Peptides". IUPAC-IUB Joint Commission on Biochemical Nomenclature. 1983. Archived from the original on 9 October 2008. Retrieved 5 March 2018.
^"IUPAC-IUBMB Joint Commission on Biochemical Nomenclature (JCBN) and Nomenclature Committee of IUBMB (NC-IUBMB)". European Journal of Biochemistry. 264 (2): 607–609. 17 August 1999. doi:10.1046/j.1432-1327.1999.news99.x.
^Johansson L, Gafvelin G, Arnér ES (October 2005). "Selenocysteine in proteins—properties and biotechnological use". Biochimica et Biophysica Acta (BBA) - General Subjects. 1726 (1): 1–13. doi:10.1016/j.bbagen.2005.05.010. hdl:10616/39311. PMID 15967579.
^"Stadtman Pioneer of Selenium Biochemistry - Office of NIH History and Stetten Museum". history.nih.gov. Retrieved 2023-04-06.
Selenocysteine (symbol Sec or U, in older publications also as Se-Cys) is the 21st proteinogenic amino acid. Selenoproteins contain selenocysteine residues...
(proteinogenic) amino acids, 20 in the standard genetic code and an additional 2 (selenocysteine and pyrrolysine) that can be incorporated by special translation mechanisms...
In biology, the SECIS element (SECIS: selenocysteine insertion sequence) is an RNA element around 60 nucleotides in length that adopts a stem-loop structure...
as forage, e.g. locoweed. Selenium is a component of the amino acids selenocysteine and selenomethionine. In humans, selenium is a trace element nutrient...
acids. Selenocysteine (Sec, U) is a rare amino acid not directly encoded by DNA, but is incorporated into proteins via the ribosome. Selenocysteine has a...
In molecular biology a selenoprotein is any protein that includes a selenocysteine (Sec, U, Se-Cys) amino acid residue. Among functionally characterized...
polyatomic also. For example, the amino acids serine, cysteine, and selenocysteine are all isoelectronic to each other. They differ by which specific chalcogen...
enzymes. This was followed by the discovery of selenocysteine in proteins. During the 1980s, selenocysteine was shown to be encoded by the codon UGA. The...
acid building blocks. Two unusual genetically-encoded amino acids are selenocysteine and pyrrolysine. Pyrrolysine was discovered in 2002 at the active site...
canonical amino acid selenocysteine (HO2CCH(NH2)CH2SeH). The compound can also be prepared synthetically from serine. Because selenocysteine is not easily isolated...
messenger RNA. For example, UGA can code for selenocysteine and UAG can code for pyrrolysine. Selenocysteine came to be seen as the 21st amino acid, and...
Of the twenty-one amino acids common to all life forms (including selenocysteine), dogs cannot synthesize ten: arginine, histidine, isoleucine, leucine...
amino acids; but in certain organisms the genetic code can include selenocysteine and—in certain archaea—pyrrolysine. Shortly after or even during synthesis...
Space Weather Prediction Center, formerly Space Environment Center Selenocysteine, an amino acid Secondary Electron Conduction Tube, part of the Apollo...
enzymes contain selenium, in the form of an otherwise rare amino acid selenocysteine. These enzymes are not to be confused with the iodotyrosine deiodinases...
are alanine, aspartic acid, asparagine, glutamic acid, serine, and selenocysteine (considered the 21st amino acid). Pyrrolysine (considered the 22nd amino...
cofactor. Each subunit contains a selenocysteine (Sec) residue which is required for catalytic activity. The selenocysteine is encoded by the UGA codon that...
codons to amino acids. In 1986, convincing evidence was provided that selenocysteine (Sec) was incorporated co-translationally. Moreover, the codon partially...
conserved stem-loop structure called the selenocysteine insertion sequence (SECIS) causes for the insertion of selenocysteine instead. The 3′-untranslated region...
the atomic numbers of atoms near the asymmetric carbon, cysteine (and selenocysteine) have R chirality, because of the presence of sulfur (or selenium) as...
a serine or cysteine amino acid, but occasionally threonine or even selenocysteine. The 3D structure of the enzyme brings together the triad residues in...
catalyze release of iodine directly from the thyronine hormones. They are selenocysteine-dependent membrane proteins with a catalytic domain resembling peroxiredoxins...
methyl selenide are found in human breath after consuming raw garlic. Selenocysteine, called the twenty-first amino acid, is essential for ribosome-directed...
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