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Pathway Description
Cysteine Biosynthesis
Escherichia coli str. K-12 substr. MG1655
Category:
Metabolite Pathway
Sub-Category:
Metabolic
Created: 2024-12-22
Last Updated: 2025-07-13
The pathway of cysteine biosynthesis is a two-step conversion starting from L-serine and yielding L-cysteine. L-serine biosynthesis is shown for context. L-cysteine can also be synthesized from sulfate derivatives. The process through L-serine involves a serine acetyltransferase that produces a O-acetylserine which reacts together with hydrogen sulfide through a cysteine synthase complex in order to produce L-cysteine and acetic acid. Hydrogen sulfide is produced from a sulfate. Sulfate reacts with sulfate adenylyltransferase to produce adenosine phosphosulfate. This compound in turn is phosphorylated through a adenylyl-sulfate kinase into a phosphoadenosine phosphosulfate which in turn reacts with a phosphoadenosine phosphosulfate reductase to produce a sulfite. The sulfite reacts with a sulfite reductase to produce the hydrogen sulfide. This pathway shows the second step of cysteine biosynthesis (at genetic level). Both cysteine synthase isozymes undergo the positive control by the cysteine-responsive transcription factor CysB. Only cysteine synthase A (CysK) forms a complex with serine acetyltransferase and it is the only cysteine synthase that is required for cell viability with cysteine-free medium. Cysteine synthases may also work as the sulfur scavenging systemfor sulfur starvation by taking sulfur off of L-cysteine.
References
Cysteine Biosynthesis References
Tobey KL, Grant GA: The nucleotide sequence of the serA gene of Escherichia coli and the amino acid sequence of the encoded protein, D-3-phosphoglycerate dehydrogenase. J Biol Chem. 1986 Sep 15;261(26):12179-83.
Pubmed: 3017965
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
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
Duncan K, Coggins JR: The serC-aro A operon of Escherichia coli. A mixed function operon encoding enzymes from two different amino acid biosynthetic pathways. Biochem J. 1986 Feb 15;234(1):49-57. doi: 10.1042/bj2340049.
Pubmed: 3518706
Drewke C, Klein M, Clade D, Arenz A, Muller R, Leistner E: 4-O-phosphoryl-L-threonine, a substrate of the pdxC(serC) gene product involved in vitamin B6 biosynthesis. FEBS Lett. 1996 Jul 22;390(2):179-82. doi: 10.1016/0014-5793(96)00652-7.
Pubmed: 8706854
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
Neuwald AF, Stauffer GV: DNA sequence and characterization of the Escherichia coli serB gene. Nucleic Acids Res. 1985 Oct 11;13(19):7025-39. doi: 10.1093/nar/13.19.7025.
Pubmed: 2997734
Burland V, Plunkett G 3rd, Sofia HJ, Daniels DL, Blattner FR: Analysis of the Escherichia coli genome VI: DNA sequence of the region from 92.8 through 100 minutes. Nucleic Acids Res. 1995 Jun 25;23(12):2105-19. doi: 10.1093/nar/23.12.2105.
Pubmed: 7610040
Denk D, Bock A: L-cysteine biosynthesis in Escherichia coli: nucleotide sequence and expression of the serine acetyltransferase (cysE) gene from the wild-type and a cysteine-excreting mutant. J Gen Microbiol. 1987 Mar;133(3):515-25. doi: 10.1099/00221287-133-3-515.
Pubmed: 3309158
Tei H, Murata K, Kimura A: Structure and expression of cysX, the second gene in the Escherichia coli K-12 cysE locus. Biochem Biophys Res Commun. 1990 Mar 30;167(3):948-55. doi: 10.1016/0006-291x(90)90615-t.
Pubmed: 2108679
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
Sirko A, Hryniewicz M, Hulanicka D, Bock A: Sulfate and thiosulfate transport in Escherichia coli K-12: nucleotide sequence and expression of the cysTWAM gene cluster. J Bacteriol. 1990 Jun;172(6):3351-7. doi: 10.1128/jb.172.6.3351-3357.1990.
Pubmed: 2188958
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
Levy S, Danchin A: Phylogeny of metabolic pathways: O-acetylserine sulphydrylase A is homologous to the tryptophan synthase beta subunit. Mol Microbiol. 1988 Nov;2(6):777-83. doi: 10.1111/j.1365-2958.1988.tb00089.x.
Pubmed: 3062311
Byrne CR, Monroe RS, Ward KA, Kredich NM: DNA sequences of the cysK regions of Salmonella typhimurium and Escherichia coli and linkage of the cysK regions to ptsH. J Bacteriol. 1988 Jul;170(7):3150-7. doi: 10.1128/jb.170.7.3150-3157.1988.
Pubmed: 3290198
Ostrowski J, Barber MJ, Rueger DC, Miller BE, Siegel LM, Kredich NM: Characterization of the flavoprotein moieties of NADPH-sulfite reductase from Salmonella typhimurium and Escherichia coli. Physicochemical and catalytic properties, amino acid sequence deduced from DNA sequence of cysJ, and comparison with NADPH-cytochrome P-450 reductase. J Biol Chem. 1989 Sep 25;264(27):15796-808.
Pubmed: 2550423
Ostrowski J, Wu JY, Rueger DC, Miller BE, Siegel LM, Kredich NM: Characterization of the cysJIH regions of Salmonella typhimurium and Escherichia coli B. DNA sequences of cysI and cysH and a model for the siroheme-Fe4S4 active center of sulfite reductase hemoprotein based on amino acid homology with spinach nitrite reductase. J Biol Chem. 1989 Sep 15;264(26):15726-37.
Pubmed: 2670946
Leyh TS, Vogt TF, Suo Y: The DNA sequence of the sulfate activation locus from Escherichia coli K-12. J Biol Chem. 1992 May 25;267(15):10405-10.
Pubmed: 1316900
Satishchandran C, Hickman YN, Markham GD: Characterization of the phosphorylated enzyme intermediate formed in the adenosine 5'-phosphosulfate kinase reaction. Biochemistry. 1992 Dec 1;31(47):11684-8. doi: 10.1021/bi00162a003.
Pubmed: 1332767
This pathway was propagated using PathWhiz -
Pon, A. et al. Pathways with PathWhiz (2015) Nucleic Acids Res. 43(Web Server issue): W552–W559.
Propagated from SMP0000821
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