Loading Pathway...
Error: Pathway image not found.
Hide
Pathway Description
L-Alanine Metabolism
Escherichia coli
Category:
Metabolite Pathway
Sub-Category:
Metabolic
Created: 2015-03-02
Last Updated: 2019-09-03
L-alanine is an essential component of proteins and peptidoglycan. The latter also contains about three molecules of D-alanine for every L-alanine. Only about 10 percent of the total alanine synthesized flows into peptidoglycan.There are at least 3 ways to begin the biosynthesis of alanine. The first method for alanine biosynthesis begins with L-cysteine produced from L-cysteine biosynthesis pathway. L-cysteine reacts with an [L-cysteine desulfurase] L-cysteine persulfide through a cysteine desulfurase resulting in a release of [L-cysteine desulfurase] l-cysteine persulfide and L-alanine. The second method starts with pyruvic acid reacting with L-glutamic acid through a glutamate-pyruvate aminotransferase resulting in a oxoglutaric acid and L-alanine. The third method starts with L-glutamic acid interacting with Alpha-ketoisovaleric acid through a valine transaminase resulting in an oxoglutaric acid and L-valine. L-valine reacts with pyruvic acid through a valine-pyruvate aminotransferase resulting Alpha-ketoisovaleric acid and L-alanine. This first step of the pathway, which can be catalyzed by either of two racemases (biosynthetic or catabolic), also serves an essential role in biosynthesis because its product, D-alanine, is an essential component of cell wall peptidoglycan (murein). D-alanine is metabolized by an ATP driven D-alanine ligase A and B resulting in D-alanyl-D-alanine. This product is incorporated into the peptidoglycan biosynthesis. L-alanine is metabolized with alanine racemase, either catabolic or metabolic resulting in a D-alanine. This compound reacts with water and a quinone through a D-amino acid dehydrogenase resulting in Pyruvic acid, hydroquinone and ammonium, thus entering the central metabolism and thereby can serve as a total source of carbon and energy. The role of the dadX racemase is degradative and dadX racemase can be induced by alanine and is subject to catabolite repression.
References
L-Alanine Metabolism References
Kaczorowski G, Shaw L, F-entes M, Walsh C: Coupling of alanine racemase and D-alanine dehydrogenase to active transport of amino acids in Escherichia coli B membrane vesicles. J Biol Chem. 1975 Apr 25;250(8):2855-65.
Pubmed: 1091641
Falkinham JO 3rd: Identification of a mutation affecting an alanine-alpha-ketoisovalerate transaminase activity in Escherichia coli K-12. Mol Gen Genet. 1979 Oct 2;176(1):147-9.
Pubmed: 396446
Whalen WA, Berg CM: Analysis of an avtA::Mu d1(Ap lac) mutant: metabolic role of transaminase C. J Bacteriol. 1982 May;150(2):739-46.
Pubmed: 7040341
Raunio RP, Jenkins WT: D-alanine oxidase form Escherichia coli: localization and induction by L-alanine. J Bacteriol. 1973 Aug;115(2):560-6.
Pubmed: 4146872
Mihara H, Esaki N: Bacterial cysteine desulfurases: their function and mechanisms. Appl Microbiol Biotechnol. 2002 Oct;60(1-2):12-23. doi: 10.1007/s00253-002-1107-4. Epub 2002 Sep 4.
Pubmed: 12382038
Kurokawa Y, Watanabe A, Yoshimura T, Esaki N, Soda K: Transamination as a side-reaction catalyzed by alanine racemase of Bacillus stearothermophilus. J Biochem. 1998 Dec 1;124(6):1163-9.
Pubmed: 9832621
Robinson AC, Kenan DJ, Sweeney J, Donachie WD: Further evidence for overlapping transcriptional units in an Escherichia coli cell envelope-cell division gene cluster: DNA sequence and transcriptional organization of the ddl ftsQ region. J Bacteriol. 1986 Sep;167(3):809-17. doi: 10.1128/jb.167.3.809-817.1986.
Pubmed: 3528126
Yura T, Mori H, Nagai H, Nagata T, Ishihama A, Fujita N, Isono K, Mizobuchi K, Nakata A: Systematic sequencing of the Escherichia coli genome: analysis of the 0-2.4 min region. Nucleic Acids Res. 1992 Jul 11;20(13):3305-8. doi: 10.1093/nar/20.13.3305.
Pubmed: 1630901
Blattner FR, Plunkett G 3rd, Bloch CA, Perna NT, Burland V, Riley M, Collado-Vides J, Glasner JD, Rode CK, Mayhew GF, Gregor J, Davis NW, Kirkpatrick HA, Goeden MA, Rose DJ, Mau B, Shao Y: The complete genome sequence of Escherichia coli K-12. Science. 1997 Sep 5;277(5331):1453-62. doi: 10.1126/science.277.5331.1453.
Pubmed: 9278503
Zawadzke LE, Bugg TD, Walsh CT: Existence of two D-alanine:D-alanine ligases in Escherichia coli: cloning and sequencing of the ddlA gene and purification and characterization of the DdlA and DdlB enzymes. Biochemistry. 1991 Feb 12;30(6):1673-82. doi: 10.1021/bi00220a033.
Pubmed: 1993184
Hayashi K, Morooka N, Yamamoto Y, Fujita K, Isono K, Choi S, Ohtsubo E, Baba T, Wanner BL, Mori H, Horiuchi T: Highly accurate genome sequences of Escherichia coli K-12 strains MG1655 and W3110. Mol Syst Biol. 2006;2:2006.0007. doi: 10.1038/msb4100049. Epub 2006 Feb 21.
Pubmed: 16738553
Yamamoto Y, Aiba H, Baba T, Hayashi K, Inada T, Isono K, Itoh T, Kimura S, Kitagawa M, Makino K, Miki T, Mitsuhashi N, Mizobuchi K, Mori H, Nakade S, Nakamura Y, Nashimoto H, Oshima T, Oyama S, Saito N, Sampei G, Satoh Y, Sivasundaram S, Tagami H, Horiuchi T, et al.: Construction of a contiguous 874-kb sequence of the Escherichia coli -K12 genome corresponding to 50.0-68.8 min on the linkage map and analysis of its sequence features. DNA Res. 1997 Apr 28;4(2):91-113. doi: 10.1093/dnares/4.2.91.
Pubmed: 9205837
Liu L, Whalen W, Das A, Berg CM: Rapid sequencing of cloned DNA using a transposon for bidirectional priming: sequence of the Escherichia coli K-12 avtA gene. Nucleic Acids Res. 1987 Nov 25;15(22):9461-9. doi: 10.1093/nar/15.22.9461.
Pubmed: 2825136
Whalen WA, Berg CM: Gratuitous repression of avtA in Escherichia coli and Salmonella typhimurium. J Bacteriol. 1984 May;158(2):571-4.
Pubmed: 6373721
Sofia HJ, Burland V, Daniels DL, Plunkett G 3rd, Blattner FR: Analysis of the Escherichia coli genome. V. DNA sequence of the region from 76.0 to 81.5 minutes. Nucleic Acids Res. 1994 Jul 11;22(13):2576-86. doi: 10.1093/nar/22.13.2576.
Pubmed: 8041620
Kuramitsu S, Ogawa T, Ogawa H, Kagamiyama H: Branched-chain amino acid aminotransferase of Escherichia coli: nucleotide sequence of the ilvE gene and the deduced amino acid sequence. J Biochem. 1985 Apr;97(4):993-9. doi: 10.1093/oxfordjournals.jbchem.a135176.
Pubmed: 3897211
Lawther RP, Nichols B, Zurawski G, Hatfield GW: The nucleotide sequence preceding and including the beginning of the ilvE gene of the ilvGEDA operon of Escherichia coli K12. Nucleic Acids Res. 1979 Dec 20;7(8):2289-301. doi: 10.1093/nar/7.8.2289.
Pubmed: 392469
Lawther RP, Wek RC, Lopes JM, Pereira R, Taillon BE, Hatfield GW: The complete nucleotide sequence of the ilvGMEDA operon of Escherichia coli K-12. Nucleic Acids Res. 1987 Mar 11;15(5):2137-55. doi: 10.1093/nar/15.5.2137.
Pubmed: 3550695
Lobocka M, Hennig J, Wild J, Klopotowski T: Organization and expression of the Escherichia coli K-12 dad operon encoding the smaller subunit of D-amino acid dehydrogenase and the catabolic alanine racemase. J Bacteriol. 1994 Mar;176(5):1500-10. doi: 10.1128/jb.176.5.1500-1510.1994.
Pubmed: 7906689
Oshima T, Aiba H, Baba T, Fujita K, Hayashi K, Honjo A, Ikemoto K, Inada T, Itoh T, Kajihara M, Kanai K, Kashimoto K, Kimura S, Kitagawa M, Makino K, Masuda S, Miki T, Mizobuchi K, Mori H, Motomura K, Nakamura Y, Nashimoto H, Nishio Y, Saito N, Horiuchi T, et al.: A 718-kb DNA sequence of the Escherichia coli K-12 genome corresponding to the 12.7-28.0 min region on the linkage map. DNA Res. 1996 Jun 30;3(3):137-55. doi: 10.1093/dnares/3.3.137.
Pubmed: 8905232
Lauhon CT, Kambampati R: The iscS gene in Escherichia coli is required for the biosynthesis of 4-thiouridine, thiamin, and NAD. J Biol Chem. 2000 Jun 30;275(26):20096-103. doi: 10.1074/jbc.M002680200.
Pubmed: 10781607
Highlighted elements will appear in red.
Highlight Compounds
Highlight Proteins
Enter relative concentration values (without units). Elements will be highlighted in a color gradient where red = lowest concentration and green = highest concentration. For the best results, view the pathway in Black and White.
Visualize Compound Data
Visualize Protein Data
Settings