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Escherichia coli K-12 substr. MG1655 Pathway: S-adenosyl-L-methionine biosynthesis
Inferred from experiment

Pathway diagram: S-adenosyl-L-methionine biosynthesis

If an enzyme name is shown in bold, there is experimental evidence for this enzymatic activity.

Locations of Mapped Genes:

Schematic showing all replicons, marked with selected genes

Genetic Regulation Schematic

Genetic regulation schematic for S-adenosyl-L-methionine biosynthesis

Synonyms: S-adenosylmethionine biosynthesis

Superclasses: BiosynthesisCofactors, Prosthetic Groups, Electron Carriers Biosynthesis

It has been said that no biological compound functions in as many different types of biological reactions as S-adenosyl-L-methionine (known as SAM or AdoMet). It is probably second only to ATP in the variety of reactions for which it serves as a cofactor. SAM is found in all living organisms, and fulfills three important roles:

* In transmethylation, SAM is the principal biological methyl donor.

* In transsulfuration, the sulfur atom of the SAM molecule is converted via a series of enzymatic steps to cysteine, a precursor of taurine and glutathione, a major cellular anti-oxidant.

* In polyamine biosynthesis, SAM is the donor of aminopropyl groups.

The structure of SAM was first elucidated by Cantoni in 1951 [Cantoni51]. The key to SAM's activity lies in the presence of the high energy sulfonium ion, which activates each of the attached carbons toward nucleophilic attack. In most cases, SAM reacts by transfer of the S-methyl group to a long list of possible acceptors in transmethylation reactions.

SAM is synthesized in the cytosol of every cell from L-methionine and ATP; in E. coli, the reaction is catalyzed by methionine adenosyltransferase. In this unusual reaction, the adenosyl moiety of ATP is transferred to methionine, forming a sulfonium ion which is a high energy reagent that can easily transfer its methyl group to a large variety of acceptor substrates including nucleic acids, proteins, phospholipids, biologic amines, and a long list of small molecules [Lu00].

Superpathways: superpathway of S-adenosyl-L-methionine biosynthesis, aspartate superpathway, S-adenosyl-L-methionine cycle I

Created 08-Jul-1994 by Riley M, Marine Biological Laboratory


Cantoni51: Cantoni GL (1951). "Methylation of nicotinamide with soluble enzyme system from rat liver." J Biol Chem 189(1);203-16. PMID: 14832232

Lu00: Lu SC (2000). "S-Adenosylmethionine." Int J Biochem Cell Biol 32(4);391-5. PMID: 10762064

Other References Related to Enzymes, Genes, Subpathways, and Substrates of this Pathway

Arifuzzaman06: Arifuzzaman M, Maeda M, Itoh A, Nishikata K, Takita C, Saito R, Ara T, Nakahigashi K, Huang HC, Hirai A, Tsuzuki K, Nakamura S, Altaf-Ul-Amin M, Oshima T, Baba T, Yamamoto N, Kawamura T, Ioka-Nakamichi T, Kitagawa M, Tomita M, Kanaya S, Wada C, Mori H (2006). "Large-scale identification of protein-protein interaction of Escherichia coli K-12." Genome Res 16(5);686-91. PMID: 16606699

BRENDA14: BRENDA team (2014). Imported from BRENDA version existing on Aug 2014.

Chattopadhyay91: Chattopadhyay MK, Ghosh AK, Sengupta S (1991). "Control of methionine biosynthesis in Escherichia coli K12: a closer study with analogue-resistant mutants." J Gen Microbiol 137(3);685-91. PMID: 2033383

DiazMejia09: Diaz-Mejia JJ, Babu M, Emili A (2009). "Computational and experimental approaches to chart the Escherichia coli cell-envelope-associated proteome and interactome." FEMS Microbiol Rev 33(1);66-97. PMID: 19054114

Fu96: Fu Z, Hu Y, Markham GD, Takusagawa F (1996). "Flexible loop in the structure of S-adenosylmethionine synthetase crystallized in the tetragonal modification." J Biomol Struct Dyn 13(5);727-39. PMID: 8723769

GOA01: GOA, MGI (2001). "Gene Ontology annotation based on Enzyme Commission mapping." Genomics 74;121-128.

GOA01a: GOA, DDB, FB, MGI, ZFIN (2001). "Gene Ontology annotation through association of InterPro records with GO terms."

GOA06: GOA, SIB (2006). "Electronic Gene Ontology annotations created by transferring manual GO annotations between orthologous microbial proteins."

Greene73: Greene RC, Hunter JS, Coch EH (1973). "Properties of metK mutants of Escherichia coli K-12." J Bacteriol 115(1);57-67. PMID: 4577753

Ishihama08: Ishihama Y, Schmidt T, Rappsilber J, Mann M, Hartl FU, Kerner MJ, Frishman D (2008). "Protein abundance profiling of the Escherichia coli cytosol." BMC Genomics 9;102. PMID: 18304323

Komoto04: Komoto J, Yamada T, Takata Y, Markham GD, Takusagawa F (2004). "Crystal structure of the S-adenosylmethionine synthetase ternary complex: a novel catalytic mechanism of S-adenosylmethionine synthesis from ATP and Met." Biochemistry 43(7);1821-31. PMID: 14967023

Lasserre06: Lasserre JP, Beyne E, Pyndiah S, Lapaillerie D, Claverol S, Bonneu M (2006). "A complexomic study of Escherichia coli using two-dimensional blue native/SDS polyacrylamide gel electrophoresis." Electrophoresis 27(16);3306-21. PMID: 16858726

LopezCampistrou05: Lopez-Campistrous A, Semchuk P, Burke L, Palmer-Stone T, Brokx SJ, Broderick G, Bottorff D, Bolch S, Weiner JH, Ellison MJ (2005). "Localization, annotation, and comparison of the Escherichia coli K-12 proteome under two states of growth." Mol Cell Proteomics 4(8);1205-9. PMID: 15911532

Markham80: Markham GD, Hafner EW, Tabor CW, Tabor H (1980). "S-Adenosylmethionine synthetase from Escherichia coli." J Biol Chem 1980;255(19);9082-92. PMID: 6251075

Markham81: Markham GD (1981). "Spatial proximity of two divalent metal ions at the active site of S-adenosylmethionine synthetase." J Biol Chem 1981;256(4);1903-9. PMID: 6257692

Markham84: Markham GD (1984). "Structure of the divalent metal ion activator binding site of S-adenosylmethionine synthetase studied by vanadyl(IV) electron paramagnetic resonance." Biochemistry 23(3);470-8. PMID: 6322838

Markham86: Markham GD (1986). "Characterization of the monovalent cation activator binding site of S-adenosylmethionine synthetase by 205Tl NMR of enzyme-bound Tl+." J Biol Chem 261(4);1507-9. PMID: 3511045

Markham87: Markham GD, Parkin DW, Mentch F, Schramm VL (1987). "A kinetic isotope effect study and transition state analysis of the S-adenosylmethionine synthetase reaction." J Biol Chem 262(12);5609-15. PMID: 3553181

Markham88: Markham GD, Satishchandran C (1988). "Identification of the reactive sulfhydryl groups of S-adenosylmethionine synthetase." J Biol Chem 263(18);8666-70. PMID: 3288619

McQueney00: McQueney MS, Anderson KS, Markham GD (2000). "Energetics of S-adenosylmethionine synthetase catalysis." Biochemistry 39(15);4443-54. PMID: 10757994

Showing only 20 references. To show more, press the button "Show all references".

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Please cite the following article in publications resulting from the use of EcoCyc: Nucleic Acids Research 41:D605-12 2013
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