Escherichia coli K-12 substr. MG1655 Pathway: L-cysteine biosynthesis I
Inferred from experiment

Pathway diagram: L-cysteine biosynthesis I

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 L-cysteine biosynthesis I

Superclasses: BiosynthesisAmino Acids BiosynthesisProteinogenic Amino Acids BiosynthesisL-cysteine Biosynthesis

The pathway of cysteine biosynthesis is a two-step conversion starting from L-serine and yielding L-cysteine.

This pathway is regulated at the genetic level in its second step, wtih both cysteine synthase isozymes being under the positive control of the cysteine-responsive transcription factor CysB. It is also subject to very strong feedback inhibition of its first step by the final pathway product, cysteine.

Although two cysteine synthase isozymes exist, only cysteine synthase A (CysK) forms a complex with serine acetyltransferase. CysK is also the only one of the two cysteine synthases that is required for cell viability on cysteine-free medium.

Both steps in this pathway are reversible. Based on genetic and proteomic data, it appears that the cysteine synthases may actually act as a sulfur scavenging system during sulfur starvation, stripping sulfur off of L-cysteine, generating any number of variant amino acids in the process.

Superpathways: superpathway of sulfate assimilation and cysteine biosynthesis

Revised 01-Jul-2009 by Caspi R, SRI International

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

Ackerley06: Ackerley DF, Barak Y, Lynch SV, Curtin J, Matin A (2006). "Effect of chromate stress on Escherichia coli K-12." J Bacteriol 188(9);3371-81. PMID: 16621832

Awano03: Awano N, Wada M, Kohdoh A, Oikawa T, Takagi H, Nakamori S (2003). "Effect of cysteine desulfhydrase gene disruption on L-cysteine overproduction in Escherichia coli." Appl Microbiol Biotechnol 62(2-3);239-43. PMID: 12883870

Awano05: Awano N, Wada M, Mori H, Nakamori S, Takagi H (2005). "Identification and functional analysis of Escherichia coli cysteine desulfhydrases." Appl Environ Microbiol 71(7);4149-52. PMID: 16000837

BacaDeLancey99: Baca-DeLancey RR, South MM, Ding X, Rather PN (1999). "Escherichia coli genes regulated by cell-to-cell signaling." Proc Natl Acad Sci U S A 96(8);4610-4. PMID: 10200310

Boronat84: Boronat A, Britton P, Jones-Mortimer MC, Kornberg HL, Lee LG, Murfitt D, Parra F (1984). "Location on the Escherichia coli genome of a gene specifying O-acetylserine (thiol)-lyase." J Gen Microbiol 130(3);673-85. PMID: 6374031

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

Byrne88: Byrne CR, Monroe RS, Ward KA, Kredich NM (1988). "DNA sequences of the cysK regions of Salmonella typhimurium and Escherichia coli and linkage of the cysK regions to ptsH." J Bacteriol 1988;170(7);3150-7. PMID: 3290198

Claus05: Claus MT, Zocher GE, Maier TH, Schulz GE (2005). "Structure of the O-acetylserine sulfhydrylase isoenzyme CysM from Escherichia coli." Biochemistry 44(24);8620-6. PMID: 15952768

Denk87: Denk D, Bock A (1987). "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;133 ( Pt 3);515-25. PMID: 3309158

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

Diner12: Diner EJ, Beck CM, Webb JS, Low DA, Hayes CS (2012). "Identification of a target cell permissive factor required for contact-dependent growth inhibition (CDI)." Genes Dev 26(5);515-25. PMID: 22333533

FeldmanSalit09: Feldman-Salit A, Wirtz M, Hell R, Wade RC (2009). "A mechanistic model of the cysteine synthase complex." J Mol Biol 386(1);37-59. PMID: 18801369

Fimmel77: Fimmel AL, Loughlin RE (1977). "Isolation and characterization of cysK mutants of Escherichia coli K12." J Gen Microbiol 103(1);37-43. PMID: 338862

Flint96: Flint DH, Tuminello JF, Miller TJ (1996). "Studies on the synthesis of the Fe-S cluster of dihydroxy-acid dehydratase in escherichia coli crude extract. Isolation of O-acetylserine sulfhydrylases A and B and beta-cystathionase based on their ability to mobilize sulfur from cysteine and to participate in Fe-S cluster synthesis." J Biol Chem 271(27);16053-67. PMID: 8663055

Fuentes07: Fuentes DE, Fuentes EL, Castro ME, Perez JM, Araya MA, Chasteen TG, Pichuantes SE, Vasquez CC (2007). "Cysteine metabolism-related genes and bacterial resistance to potassium tellurite." J Bacteriol 189(24);8953-60. PMID: 17951385

Gao13: Gao Y, Peng X, Zhang J, Zhao J, Li Y, Li B, Hu Y, Chai Z (2013). "Cellular response of E. coli upon Hg2+ exposure--a case study of advanced nuclear analytical approach to metalloproteomics." Metallomics 5(7);913-9. PMID: 23771180

Gaudet10: Gaudet P, Livstone M, Thomas P (2010). "Annotation inferences using phylogenetic trees." PMID: 19578431

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."

Hayes14: Hayes CS, Koskiniemi S, Ruhe ZC, Poole SJ, Low DA (2014). "Mechanisms and biological roles of contact-dependent growth inhibition systems." Cold Spring Harb Perspect Med 4(2). PMID: 24492845

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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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