S-Adenosyl-L-homocysteine

Last updated
S-Adenosyl-L-homocysteine
S-Adenosyl-L-homocystein.svg
Names
IUPAC name
S-(5′-Deoxyadenos-5′-yl)-L-homocysteine
Systematic IUPAC name
(2S)-2-Amino-4-({[(2S,3S,4R,5R)-5-(6-amino-9H-purin-9-yl)-3,4-dihydroxyoxolan-2-yl]methyl}sulfanyl)butanoic acid
Other names
AdoHcy, 2-S-adenosyl-L-homocysteine,
5′-S-(3-Amino-3-carboxypropyl)-5′-thioadenosine S-adenosylhomocysteine, SAH
Identifiers
3D model (JSmol)
ChEBI
ChEMBL
ChemSpider
ECHA InfoCard 100.012.328 OOjs UI icon edit-ltr-progressive.svg
KEGG
MeSH S-Adenosylhomocysteine
PubChem CID
UNII
  • InChI=1S/C14H20N6O5S/c15-6(14(23)24)1-2-26-3-7-9(21)10(22)13(25-7)20-5-19-8-11(16)17-4-18-12(8)20/h4-7,9-10,13,21-22H,1-3,15H2,(H,23,24)(H2,16,17,18)/t6-,7+,9+,10+,13+/m0/s1 Yes check.svgY
    Key: ZJUKTBDSGOFHSH-WFMPWKQPSA-N Yes check.svgY
  • InChI=1/C14H20N6O5S/c15-6(14(23)24)1-2-26-3-7-9(21)10(22)13(25-7)20-5-19-8-11(16)17-4-18-12(8)20/h4-7,9-10,13,21-22H,1-3,15H2,(H,23,24)(H2,16,17,18)/t6-,7+,9+,10+,13+/m0/s1
    Key: ZJUKTBDSGOFHSH-WFMPWKQPBX
  • O=C(O)[C@@H](N)CCSC[C@H]3O[C@@H](n2cnc1c(ncnc12)N)[C@H](O)[C@@H]3O
Properties
C14H20N6O5S
Molar mass 384.41 g·mol−1
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
Yes check.svgY  verify  (what is  Yes check.svgYX mark.svgN ?)

S-Adenosyl-L-homocysteine (SAH) is the biosynthetic precursor to homocysteine. [1] SAH is formed by the demethylation of S-adenosyl-L-methionine. [2] [3] Adenosylhomocysteinase converts SAH into homocysteine and adenosine.

Contents

Biological role

DNA methyltransferases are inhibited by SAH. [4] Two S-adenosyl-L-homocysteine cofactor products can bind the active site of DNA methyltransferase 3B and prevent the DNA duplex from binding to the active site, which inhibits DNA methylation. [5]

Related Research Articles

<i>S</i>-Adenosyl methionine Chemical compound found in all domains of life with largely unexplored effects

S-Adenosyl methionine (SAM), also known under the commercial names of SAMe, SAM-e, or AdoMet, is a common cosubstrate involved in methyl group transfers, transsulfuration, and aminopropylation. Although these anabolic reactions occur throughout the body, most SAM is produced and consumed in the liver. More than 40 methyl transfers from SAM are known, to various substrates such as nucleic acids, proteins, lipids and secondary metabolites. It is made from adenosine triphosphate (ATP) and methionine by methionine adenosyltransferase. SAM was first discovered by Giulio Cantoni in 1952.

<span class="mw-page-title-main">Methyltransferase</span> Group of methylating enzymes

Methyltransferases are a large group of enzymes that all methylate their substrates but can be split into several subclasses based on their structural features. The most common class of methyltransferases is class I, all of which contain a Rossmann fold for binding S-Adenosyl methionine (SAM). Class II methyltransferases contain a SET domain, which are exemplified by SET domain histone methyltransferases, and class III methyltransferases, which are membrane associated. Methyltransferases can also be grouped as different types utilizing different substrates in methyl transfer reactions. These types include protein methyltransferases, DNA/RNA methyltransferases, natural product methyltransferases, and non-SAM dependent methyltransferases. SAM is the classical methyl donor for methyltransferases, however, examples of other methyl donors are seen in nature. The general mechanism for methyl transfer is a SN2-like nucleophilic attack where the methionine sulfur serves as the leaving group and the methyl group attached to it acts as the electrophile that transfers the methyl group to the enzyme substrate. SAM is converted to S-Adenosyl homocysteine (SAH) during this process. The breaking of the SAM-methyl bond and the formation of the substrate-methyl bond happen nearly simultaneously. These enzymatic reactions are found in many pathways and are implicated in genetic diseases, cancer, and metabolic diseases. Another type of methyl transfer is the radical S-Adenosyl methionine (SAM) which is the methylation of unactivated carbon atoms in primary metabolites, proteins, lipids, and RNA.

Site-specific DNA-methyltransferase (cytosine-N4-specific) is an enzyme with systematic name S-adenosyl-L-methionine:DNA-cytosine N4-methyltransferase. This enzyme catalyses the following chemical reaction

<span class="mw-page-title-main">DNA adenine methylase</span> Prokaryotic enzyme

DNA adenine methylase, (Dam methylase) (also site-specific DNA-methyltransferase (adenine-specific), EC 2.1.1.72, modification methylase, restriction-modification system) is an enzyme that adds a methyl group to the adenine of the sequence 5'-GATC-3' in newly synthesized DNA. Immediately after DNA synthesis, the daughter strand remains unmethylated for a short time. It is an orphan methyltransferase that is not part of a restriction-modification system and regulates gene expression. This enzyme catalyses the following chemical reaction

<span class="mw-page-title-main">DNMT3B</span> Protein-coding gene in the species Homo sapiens

DNA (cytosine-5)-methyltransferase 3 beta, is an enzyme that in humans in encoded by the DNMT3B gene. Mutation in this gene are associated with immunodeficiency, centromere instability and facial anomalies syndrome.

In enzymology, an isoflavone 7-O-methyltransferase is an enzyme that catalyzes the chemical reaction

mRNA (guanine-N7-)-methyltransferase Enzyme

In enzymology, a mRNA (guanine-N7-)-methyltransferase also known as mRNA cap guanine-N7 methyltransferase is an enzyme that catalyzes the chemical reaction

<span class="mw-page-title-main">NNMT</span> Protein-coding gene in the species Homo sapiens

Nicotinamide N-methyltransferase (NNMT) is an enzyme that in humans is encoded by the NNMT gene. NNMT catalyzes the methylation of nicotinamide and similar compounds using the methyl donor S-adenosyl methionine (SAM-e) to produce S-adenosyl-L-homocysteine (SAH) and 1-methylnicotinamide.

<span class="mw-page-title-main">Uroporphyrinogen-III C-methyltransferase</span> Class of enzymes

Uroporphyrinogen-III C-methyltransferase, uroporphyrinogen methyltransferase, uroporphyrinogen-III methyltransferase, adenosylmethionine-uroporphyrinogen III methyltransferase, S-adenosyl-L-methionine-dependent uroporphyrinogen III methylase, uroporphyrinogen-III methylase, SirA, CysG, CobA, uroporphyrin-III C-methyltransferase, S-adenosyl-L-methionine:uroporphyrin-III C-methyltransferase) is an enzyme with systematic name S-adenosyl-L-methionine:uroporphyrinogen-III C-methyltransferase. This enzyme catalyses the following chemical reaction

Glycine/sarcosine N-methyltransferase is an enzyme with systematic name S-adenosyl-L-methionine:glycine(or sarcosine) N-methyltransferase . This enzyme catalyses the following chemical reaction

23S rRNA (uridine2552-2'-O)-methyltransferase is an enzyme with systematic name S-adenosyl-L-methionine:23S rRNA (uridine2552-2'-O-)-methyltransferase. This enzyme catalyses the following chemical reaction

16S rRNA (guanine1405-N7)-methyltransferase (EC 2.1.1.179, methyltransferase Sgm, m7G1405 Mtase, Sgm Mtase, Sgm, sisomicin-gentamicin methyltransferase, sisomicin-gentamicin methylase, GrmA, RmtB, RmtC, ArmA) is an enzyme with systematic name S-adenosyl-L-methionine:16S rRNA (guanine1405-N7)-methyltransferase. This enzyme catalyses the following chemical reaction

23S rRNA (adenine2085-N6)-dimethyltransferase (EC 2.1.1.184, ErmC' methyltransferase, ermC methylase, ermC 23S rRNA methyltransferase, rRNA:m6A methyltransferase ErmC', ErmC', rRNA methyltransferase ErmC' ) is an enzyme with systematic name S-adenosyl-L-methionine:23S rRNA (adenine2085-N6)-dimethyltransferase. This enzyme catalyses the following chemical reaction

23S rRNA (guanine745-N1)-methyltransferase (EC 2.1.1.187, Rlma(I), Rlma1, 23S rRNA m1G745 methyltransferase, YebH, RlmAI methyltransferase, ribosomal RNA(m1G)-methylase, rRNA(m1G)methylase, RrmA, 23S rRNA:m1G745 methyltransferase) is an enzyme with systematic name S-adenosyl-L-methionine:23S rRNA (guanine745-N1)-methyltransferase. This enzyme catalyses the following chemical reaction

23S rRNA (adenine2503-C2)-methyltransferase (EC 2.1.1.192, RlmN, YfgB, Cfr) is an enzyme with systematic name S-adenosyl-L-methionine:23S rRNA (adenine2503-C2)-methyltransferase. This enzyme catalyses the following chemical reaction

23S rRNA (adenine2503-C2,C8)-dimethyltransferase (EC 2.1.1.194, Cfr, Cfr methyltransferase, Cfr rRNA methyltransferase) is an enzyme with systematic name S-adenosyl-L-methionine:23S rRNA (adenine2503-C2,C8)-dimethyltransferase. This enzyme catalyses the following chemical reaction

Multisite-specific tRNA:(cytosine-C5)-methyltransferase is an enzyme with systematic name S-adenosyl-L-methionine:tRNA (cytosine-C5)-methyltransferase. This enzyme catalyses the following chemical reaction

TRNA (cytosine38-C5)-methyltransferase is an enzyme with the systematic name S-adenosyl-L-methionine:tRNA (cytosine38-C5)-methyltransferase. This enzyme catalyses the following chemical reaction:

23S rRNA (adenine2503-C8)-methyltransferase (EC 2.1.1.224, Cfr (gene)) is an enzyme with systematic name S-adenosyl-L-methionine:23S rRNA (adenine2503-C8)-methyltransferase. This enzyme catalyses the following chemical reaction

RRNA small subunit pseudouridine methyltransferase Nep1 (EC 2.1.1.260, Nep1, nucleolar essential protein 1) is an enzyme with systematic name S-adenosyl-L-methionine:18S rRNA (pseudouridine1191-N1)-methyltransferase. This enzyme catalyses the following chemical reaction

References

  1. ↑ Finkelstein JD (2000). "Pathways and regulation of homocysteine metabolism in mammals". Seminars in Thrombosis and Hemostasis. 26 (3): 219–225. doi:10.1055/s-2000-8466. PMID   11011839.
  2. ↑ Ribbe MW, Hu Y, Hodgson KO, Hedman B (April 2014). "Biosynthesis of nitrogenase metalloclusters". Chemical Reviews. 114 (8): 4063–4080. doi:10.1021/cr400463x. PMC   3999185 . PMID   24328215.
  3. ↑ James SJ, Melnyk S, Pogribna M, Pogribny IP, Caudill MA (August 2002). "Elevation in S-adenosylhomocysteine and DNA hypomethylation: potential epigenetic mechanism for homocysteine-related pathology". The Journal of Nutrition. 132 (8 Suppl): 2361S–2366S. doi: 10.1093/jn/132.8.2361S . PMID   12163693.
  4. ↑ Kumar R, Srivastava R, Singh RK, Surolia A, Rao DN (March 2008). "Activation and inhibition of DNA methyltransferases by S-adenosyl-L-homocysteine analogues". Bioorganic & Medicinal Chemistry. 16 (5): 2276–2285. doi:10.1016/j.bmc.2007.11.075. PMID   18083524.
  5. ↑ Lin CC, Chen YP, Yang WZ, Shen JC, Yuan HS (April 2020). "Structural insights into CpG-specific DNA methylation by human DNA methyltransferase 3B". Nucleic Acids Research. 48 (7): 3949–3961. doi:10.1093/nar/gkaa111. PMC   7144912 . PMID   32083663.
This page is based on this Wikipedia article
Text is available under the CC BY-SA 4.0 license; additional terms may apply.
Images, videos and audio are available under their respective licenses.