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MetaCyc Pathway: L-cysteine degradation II
Inferred from experiment

Pathway diagram: L-cysteine degradation II

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.

Synonyms: L-cysteine catabolism, L-cysteine degradation

Superclasses: Degradation/Utilization/AssimilationAmino Acids DegradationProteinogenic Amino Acids DegradationL-cysteine Degradation

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

Expected Taxonomic Range: Bacteria , Eukaryota

General Background

This route of L-cysteine degradation is shared among bacteria and eukaryotes. Additional mammalian pathways are shown in L-cysteine degradation I and L-cysteine degradation III.

About this pathway

In Escherichia coli, L-cysteine degradation is carried out by L-cysteine desulfhydrase activity (CD) [Nakamori98]. CD is known to catalyze the degradation of L-cysteine to pyruvate, ammonia, and hydrogen sulfide [Delwiche51, Metaxas55, Awano03, Awano05]. In Escherichia coli, cystathionine-β-lyase (MetC), primarily catalyzes the conversion of L-cystathionine to L-homocysteine, pyruvate, and ammonia [Dwivedi82] while tryptophanase (TnaA) mainly degrades L-tryptophan to indole, pyruvate, and ammonia [Newton64]. Both of them have been shown to exhibit CD activity in vitro and in vivo [Cantarow78, Wang92a, Awano03].

It was recently found that in addition to tryptophanase (TnaA) and cystathionine-β-lyase (MetC), three additional proteins exhibit the PLP-dependent-L-cysteine desulfhydrase (CD) activity. These are OAS sulfhydrylase A (CysK), OAS sulfhydrylase B (CysM), and the MalY protein. CysK primarily catalyzes the synthesis of L-cysteine from O-acetyl-L-serine and hydrogen sulfide along the L-cysteine biosynthetic pathway ( L-cysteine biosynthesis I). CysM is considered to be an isomer of CysK with unidentified function. MalY protein has activity of the carbon-sulfur bond cleavage (β C-S lyase) of L-cystathionine. The gene disruption for each protein significantly decreases the CD activity and is effective for overproduction of L-cysteine. The decrease in CD activity for all these genes disruption is reversed in the presence of L-cysteine except for the tnaA gene disruption. This result suggests that TnaA is a key enzyme in L-cysteine degradation in Escherichia coli. Disruption of all the tnaA, metC, cysK, cysM and malY genes together also show much higher CD activity in the presence of L-cysteine than in its absence [Awano05, Yamada06]. Unidentified proteins with CD activity are found, which may be induced by L-cysteine.

Amino acids, L-tryptophan, L-glutamate, and L-alanine inhibit the CD activity in Escherichia coli. L-alanine, which is most similar to L-cysteine in configuration, shows the greatest amount of inhibition. Tris-(hydroxymethyl)aminomethane ( tris), an effective carbonyl agent also caused significant inhibition to the CD activity [Metaxas55].

Variants: L-cysteine degradation I, L-cysteine degradation III

Unification Links: EcoCyc:LCYSDEG-PWY

Reviewed 30-Mar-2010 by Sarker M


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

Cantarow78: Cantarow WD, Cheung HT, Sundharadas G (1978). "Effects of prostaglandins on the spreading, adhesion and migration of mouse peritoneal macrophages." Prostaglandins 16(1);39-46. PMID: 704923

Delwiche51: Delwiche EA (1951). "Activators for the cysteine desulfhydrase system of an Escherichia coli mutant." J Bacteriol 62(6);717-22. PMID: 14907623

Dwivedi82: Dwivedi CM, Ragin RC, Uren JR (1982). "Cloning, purification, and characterization of beta-cystathionase from Escherichia coli." Biochemistry 1982;21(13);3064-9. PMID: 7049234

Metaxas55: Metaxas MA, Delwiche EA (1955). "The L-cysteine desulfhydrase of Escherichia coli." J Bacteriol 70(6);735-7. PMID: 13271322

Nakamori98: Nakamori S, Kobayashi SI, Kobayashi C, Takagi H (1998). "Overproduction of L-cysteine and L-cystine by Escherichia coli strains with a genetically altered serine acetyltransferase." Appl Environ Microbiol 64(5);1607-11. PMID: 9572924

Newton64: Newton WA, Snell EE (1964). "Catalytic properties of tryptophanase, a multifunctional pyridoxal phosphate enzyme." Proc Natl Acad Sci U S A 51;382-9. PMID: 14171448

Wang92a: Wang DY, De Stavola BL, Bulbrook RD, Allen DS, Kwa HG, Fentiman IS, Hayward JL, Millis RR (1992). "Relationship of blood prolactin levels and the risk of subsequent breast cancer." Int J Epidemiol 21(2);214-21. PMID: 1428472

Yamada06: Yamada S, Awano N, Inubushi K, Maeda E, Nakamori S, Nishino K, Yamaguchi A, Takagi H (2006). "Effect of drug transporter genes on cysteine export and overproduction in Escherichia coli." Appl Environ Microbiol 72(7);4735-42. PMID: 16820466

Other 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

Atsumi10a: Atsumi S, Wu TY, Machado IM, Huang WC, Chen PY, Pellegrini M, Liao JC (2010). "Evolution, genomic analysis, and reconstruction of isobutanol tolerance in Escherichia coli." Mol Syst Biol 6;449. PMID: 21179021

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

Bairoch93: Bairoch A, Boeckmann B (1993). "The SWISS-PROT protein sequence data bank, recent developments." Nucleic Acids Res. 21:3093-3096. PMID: 8332529

Belfaiza86: Belfaiza J, Parsot C, Martel A, de la Tour CB, Margarita D, Cohen GN, Saint-Girons I (1986). "Evolution in biosynthetic pathways: two enzymes catalyzing consecutive steps in methionine biosynthesis originate from a common ancestor and possess a similar regulatory region." Proc Natl Acad Sci U S A 83(4);867-71. PMID: 3513164

Bertoldi05: Bertoldi M, Cellini B, Laurents DV, Borri Voltattorni C (2005). "Folding pathway of the pyridoxal 5'-phosphate C-S lyase MalY from Escherichia coli." Biochem J 389(Pt 3);885-98. PMID: 15823094

Bilezikian67: Bilezikian JP, Kaempfer RO, Magasanik B (1967). "Mechanism of tryptophanase induction in Escherichia coli." J Mol Biol 27(3);495-506. PMID: 4860581

Blankenhorn99: Blankenhorn D, Phillips J, Slonczewski JL (1999). "Acid- and base-induced proteins during aerobic and anaerobic growth of Escherichia coli revealed by two-dimensional gel electrophoresis." J Bacteriol 181(7);2209-16. PMID: 10094700

Bordi03: Bordi C, Theraulaz L, Mejean V, Jourlin-Castelli C (2003). "Anticipating an alkaline stress through the Tor phosphorelay system in Escherichia coli." Mol Microbiol 48(1);211-23. PMID: 12657056

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

Botsford71: Botsford JL, DeMoss RD (1971). "Catabolite repression of tryptophanase in Escherichia coli." J Bacteriol 105(1);303-12. PMID: 4322348

Botsford75: Botsford JL (1975). "Metabolism of cyclic adenosine 3',5'-monophosphate and induction of tryptophanase in Escherichia coli." J Bacteriol 124(1);380-90. PMID: 170248

Burns62: Burns RO, Demoss RD (1962). "Properties of tryptophanase from Escherichia coli." Biochim Biophys Acta 65;233-44. PMID: 14017164

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

Chant07: Chant EL, Summers DK (2007). "Indole signalling contributes to the stable maintenance of Escherichia coli multicopy plasmids." Mol Microbiol 63(1);35-43. PMID: 17163976

Chattoraj07: Chattoraj DK (2007). "Tryptophanase in sRNA control of the Escherichia coli cell cycle." Mol Microbiol 63(1);1-3. PMID: 17163965

Chu12: Chu W, Zere TR, Weber MM, Wood TK, Whiteley M, Hidalgo-Romano B, Valenzuela E, McLean RJ (2012). "Indole production promotes Escherichia coli mixed-culture growth with Pseudomonas aeruginosa by inhibiting quorum signaling." Appl Environ Microbiol 78(2);411-9. PMID: 22101045

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

Clausen00: Clausen T, Schlegel A, Peist R, Schneider E, Steegborn C, Chang YS, Haase A, Bourenkov GP, Bartunik HD, Boos W (2000). "X-ray structure of MalY from Escherichia coli: a pyridoxal 5'-phosphate-dependent enzyme acting as a modulator in mal gene expression." EMBO J 19(5);831-42. PMID: 10698925

Clausen96: Clausen T, Huber R, Laber B, Pohlenz HD, Messerschmidt A (1996). "Crystal structure of the pyridoxal-5'-phosphate dependent cystathionine beta-lyase from Escherichia coli at 1.83 A." J Mol Biol 262(2);202-24. PMID: 8831789

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 MetaCyc: Caspi et al, Nucleic Acids Research 42:D459-D471 2014
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