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/Assimilation → Amino Acids Degradation → Proteinogenic Amino Acids Degradation → L-cysteine Degradation|
Some taxa known to possess this pathway include : Escherichia coli K-12 substr. MG1655
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, Wang92, 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].
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
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
Wang92: 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
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
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
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
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
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
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
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