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discounted EARLY registration ends Dec 31, 2014
BioCyc websites down
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for maintenance.
Metabolic Modeling Tutorial
discounted EARLY registration ends Dec 31, 2014
BioCyc websites down
12/28 - 12/31
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discounted EARLY registration ends Dec 31, 2014
BioCyc websites down
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MetaCyc Pathway: homoserine biosynthesis

This view shows enzymes only for those organisms listed below, in the list of taxa known to possess the pathway. If an enzyme name is shown in bold, there is experimental evidence for this enzymatic activity.

Superclasses: Biosynthesis Amino Acids Biosynthesis Individual Amino Acids Biosynthesis Other Amino Acid Biosynthesis

Some taxa known to possess this pathway include ? : Escherichia coli K-12 substr. MG1655

Expected Taxonomic Range: Bacteria , Fungi , Viridiplantae

Summary:
The homoserine biosynthesis pathway is a three-step pathway that converts L-aspartate into homoserine. Two of the three enzymes that catalyze the first step in this pathway are bifunctional, also serving to catalyze the final step in the pathway.

The final product of this pathway, homoserine, feeds into biosynthetic pathways for both threonine and methionine. Fittingly, this pathway is regulated by the outputs of both of those pathways. metL is repressed by abundant methionine. thrA is regulated by threonine- and isoleucine-dependent attenuation, and both the aspartate kinase and homoserine dehydrogenase activities of ThrA are inhibited by threonine. The middle enzymatic activity, aspartate semialdehyde dehydrogenase, is subject to some form of repression by both methionine and threonine.

Superpathways: isoleucine biosynthesis I , threonine biosynthesis , superpathway of lysine, threonine and methionine biosynthesis II , superpathway of methionine biosynthesis (transsulfuration) , superpathway of methionine biosynthesis (by sulfhydrylation) , homoserine and methionine biosynthesis , superpathway of lysine, threonine and methionine biosynthesis I , aspartate superpathway , superpathway of S-adenosyl-L-methionine biosynthesis

Unification Links: EcoCyc:HOMOSERSYN-PWY

Credits:
Created 14-Oct-1998 by Paley S , SRI International
Last-Curated ? 16-Aug-2007 by Shearer A , SRI International


References

Chassagnole01: Chassagnole C, Rais B, Quentin E, Fell DA, Mazat JP (2001). "An integrated study of threonine-pathway enzyme kinetics in Escherichia coli." Biochem J 356(Pt 2);415-23. PMID: 11368768

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

Alvarez04: Alvarez E, Ramon F, Magan C, Diez E (2004). "L-cystine inhibits aspartate-beta-semialdehyde dehydrogenase by covalently binding to the essential 135Cys of the enzyme." Biochim Biophys Acta 1696(1);23-9. PMID: 14726201

Angeles89: Angeles TS, Smanik PA, Borders CL, Viola RE (1989). "Aspartokinase-homoserine dehydrogenase I from Escherichia coli: pH and chemical modification studies of the kinase activity." Biochemistry 28(22);8771-7. PMID: 2557908

Angeles90: Angeles TS, Viola RE (1990). "The kinetic mechanisms of the bifunctional enzyme aspartokinase-homoserine dehydrogenase I from Escherichia coli." Arch Biochem Biophys 283(1);96-101. PMID: 2241177

Bearer78: Bearer CF, Neet KE (1978). "Threonine inhibition of the aspartokinase--homoserine dehydrogenase I of Escherichia coli. A slow transient and cooperativity of inhibition of the aspartokinase activity." Biochemistry 1978;17(17);3523-30. PMID: 28752

Bearer78a: Bearer CF, Neet KE (1978). "Threonine inhibition of the aspartokinase--homoserine dehydrogenase I of Escherichia coli. Stopped-flow kinetics and the cooperativity of inhibition of the homoserine dehydrogenase activity." Biochemistry 17(17);3517-22. PMID: 28751

Bearer78b: Bearer CF, Neet KE (1978). "Threonine inhibition of the aspartokinase--homoserine dehydrogenase I of Escherichia coli. Threonine binding studies." Biochemistry 17(17);3512-6. PMID: 28750

Belfaiza84: Belfaiza J, Fazel A, Muller K, Cohen GN (1984). "E. coli aspartokinase II-homoserine dehydrogenase II polypeptide chain has a triglobular structure." Biochem Biophys Res Commun 123(1);16-20. PMID: 6383377

Biellmann80: Biellmann JF, Eid P, Hirth C, Jornvall H (1980). "Aspartate-beta-semialdehyde dehydrogenase from Escherichia coli. Purification and general properties." Eur J Biochem 1980;104(1);53-8. PMID: 6102909

Biellmann80a: Biellmann JF, Eid P, Hirth C (1980). "Affinity labeling of the Escherichia coli aspartate-beta-semialdehyde dehydrogenase with an alkylating coenzyme analogue. Half-site reactivity and competition with the substrate alkylating analogue." Eur J Biochem 1980;104(1);65-9. PMID: 6102911

Blanco03: Blanco J, Moore RA, Kabaleeswaran V, Viola RE (2003). "A structural basis for the mechanism of aspartate-beta-semialdehyde dehydrogenase from Vibrio cholerae." Protein Sci 12(1);27-33. PMID: 12493825

Boy72: Boy E, Patte JC (1972). "Multivalent repression of aspartic semialdehyde dehydrogenase in Escherichia coli K-12." J Bacteriol 112(1);84-92. PMID: 4404058

Boy79: Boy E, Borne F, Patte JC (1979). "Isolation and identification of mutants constitutive for aspartokinase III synthesis in Escherichia coli K 12." Biochimie 61(10);1151-60. PMID: 231461

BRENDA14: BRENDA team (2014). "Imported from BRENDA version existing on Aug 2014." http://www.brenda-enzymes.org.

Broglie83: Broglie KE, Takahashi M (1983). "Fluorescence studies of threonine-promoted conformational transitions in aspartokinase I using the substrate analogue 2'(3')-O-(2,4,6-trinitrophenyl)adenosine 5'-triphosphate." J Biol Chem 1983;258(21);12940-6. PMID: 6313682

Cassan75: Cassan M, Boy E, Borne F, Patte JC (1975). "Regulation of the lysine biosynthetic pathway in Escherichia coli K-12: isolation of a cis-dominant constitutive mutant for AK III synthesis." J Bacteriol 123(2);391-9. PMID: 238953

Cassan83: Cassan M, Ronceray J, Patte JC (1983). "Nucleotide sequence of the promoter region of the E. coli lysC gene." Nucleic Acids Res 11(18);6157-66. PMID: 6312411

Cassan86: Cassan M, Parsot C, Cohen GN, Patte JC (1986). "Nucleotide sequence of lysC gene encoding the lysine-sensitive aspartokinase III of Escherichia coli K12. Evolutionary pathway leading to three isofunctional enzymes." J Biol Chem 1986;261(3);1052-7. PMID: 3003049

Chen93a: Chen NY, Jiang SQ, Klein DA, Paulus H (1993). "Organization and nucleotide sequence of the Bacillus subtilis diaminopimelate operon, a cluster of genes encoding the first three enzymes of diaminopimelate synthesis and dipicolinate synthase." J Biol Chem 268(13);9448-65. PMID: 8098035

Clark72: Clark RB, Ogilvie JW (1972). "Aspartokinase I-homoserine dehydrogenase I of Escherichia coli K12 .Subunit molecular weight and nicotinamide-adenine dinucleotide phosphate binding." Biochemistry 11(7);1278-82. PMID: 4401168

Cohen85: Cohen GN (1985). "Aspartate-semialdehyde dehydrogenase from Escherichia coli." Methods Enzymol 113;600-2. PMID: 2868399

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


Report Errors or Provide Feedback
Please cite the following article in publications resulting from the use of MetaCyc: Caspi et al, Nucleic Acids Research 42:D459-D471 2014
Page generated by SRI International Pathway Tools version 18.5 on Fri Dec 19, 2014, biocyc14.