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Escherichia coli K-12 substr. MG1655 Pathway: cyanate degradation
Inferred from experiment

Pathway diagram: cyanate degradation

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 cyanate degradation

Synonyms: cyanate catabolism

Superclasses: Degradation/Utilization/AssimilationInorganic Nutrients MetabolismNitrogen Compounds Metabolism

Cyanate can occur inside the cell as a result of nonenzymatic decomposition of carbamoyl phosphate, and in the environment due to dissociation of urea and photooxidation of cyanide. Although cyanate at high concentrations is toxic to E. coli, it can serve as a sole source of nitrogen due to the production of ammonia by cyanase [Sung87]. The cyanate degradation pathway therefore serves the dual purpose of detoxification and nitrogen utilization [Kozliak95].

Cyanase catalyzes the first step of the pathway, producing CO2 and the unstable compound carbamate. Carbamate spontaneously decomposes to CO2 and ammonia, thus producing a source of nitrogen for growth. The second enzyme of this pathway, carbonic anhydrase, is an essential component of the pathway. In the absence of carbonic anhydrase at atmospheric concentrations of CO2, non-enzymatic hydration of CO2 is not sufficient to prevent depletion of the intracellular bicarbonate pool due to rapid diffusion of CO2 [Guilloton93].

Created 09-Sep-1994 by Riley M, Marine Biological Laboratory
Revised 20-Mar-2007 by Keseler I, SRI International
Last-Curated 29-Mar-2007 by Keseler I, SRI International


Guilloton93: Guilloton MB, Lamblin AF, Kozliak EI, Gerami-Nejad M, Tu C, Silverman D, Anderson PM, Fuchs JA (1993). "A physiological role for cyanate-induced carbonic anhydrase in Escherichia coli." J Bacteriol 1993;175(5);1443-51. PMID: 8444806

Kozliak95: Kozliak EI, Fuchs JA, Guilloton MB, Anderson PM (1995). "Role of bicarbonate/CO2 in the inhibition of Escherichia coli growth by cyanate." J Bacteriol 177(11);3213-9. PMID: 7768821

Sung87: Sung YC, Parsell D, Anderson PM, Fuchs JA (1987). "Identification, mapping, and cloning of the gene encoding cyanase in Escherichia coli K-12." J Bacteriol 169(6);2639-42. PMID: 3034861

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

Anderson80: Anderson PM (1980). "Purification and properties of the inducible enzyme cyanase." Biochemistry 19(13);2882-8. PMID: 6994799

Anderson86: Anderson PM, Little RM (1986). "Kinetic properties of cyanase." Biochemistry 25(7);1621-6. PMID: 3518792

Anderson87: Anderson PM, Johnson WV, Endrizzi JA, Little RM, Korte JJ (1987). "Interaction of mono- and dianions with cyanase: evidence for apparent half-site binding." Biochemistry 26(13);3938-43. PMID: 3651424

Anderson88a: Anderson PM, Johnson WV, Korte JJ, Xiong XF, Sung YC, Fuchs JA (1988). "Reversible dissociation of active octamer of cyanase to inactive dimer promoted by alteration of the sulfhydryl group." J Biol Chem 263(12);5674-80. PMID: 3128546

Anderson90: Anderson PM, Sung YC, Fuchs JA (1990). "The cyanase operon and cyanate metabolism." FEMS Microbiol Rev 1990;7(3-4);247-52. PMID: 2094285

Anderson94: Anderson PM, Korte JJ, Holcomb TA, Cho YG, Son CM, Sung YC (1994). "Formation of intersubunit disulfide bonds and properties of the single histidine and cysteine residues in each subunit relative to the decameric structure of cyanase." J Biol Chem 269(21);15036-45. PMID: 8195141

Anderson94a: Anderson PM, Korte JJ, Holcomb TA (1994). "Reaction of the N-terminal methionine residues in cyanase with diethylpyrocarbonate." Biochemistry 1994;33(47);14121-5. PMID: 7947823

Chin83: Chin CC, Anderson PM, Wold F (1983). "The amino acid sequence of Escherichia coli cyanase." J Biol Chem 258(1);276-82. PMID: 6336748

Cronk01: Cronk JD, Endrizzi JA, Cronk MR, O'neill JW, Zhang KY (2001). "Crystal structure of E. coli beta-carbonic anhydrase, an enzyme with an unusual pH-dependent activity." Protein Sci 10(5);911-22. PMID: 11316870

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

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."

GOA06: GOA, SIB (2006). "Electronic Gene Ontology annotations created by transferring manual GO annotations between orthologous microbial proteins."

Guilloton87: Guilloton M, Karst F (1987). "Isolation and characterization of Escherichia coli mutants lacking inducible cyanase." J Gen Microbiol 133(3);645-53. PMID: 3309165

Guilloton92: Guilloton MB, Korte JJ, Lamblin AF, Fuchs JA, Anderson PM (1992). "Carbonic anhydrase in Escherichia coli. A product of the cyn operon." J Biol Chem 1992;267(6);3731-4. PMID: 1740425

Hashimoto03: Hashimoto M, Kato J (2003). "Indispensability of the Escherichia coli carbonic anhydrases YadF and CynT in cell proliferation at a low CO2 partial pressure." Biosci Biotechnol Biochem 67(4);919-22. PMID: 12784642

Johnson87: Johnson WV, Anderson PM (1987). "Bicarbonate is a recycling substrate for cyanase." J Biol Chem 262(19);9021-5. PMID: 3110153

Kozliak00: Kozliak EI, Guilloton MB, Fuchs JA, Anderson PM (2000). "Bacterial carbonic anhydrases." EXS (90);547-65. PMID: 11268536

Kozliak94: Kozliak EI, Guilloton MB, Gerami-Nejad M, Fuchs JA, Anderson PM (1994). "Expression of proteins encoded by the Escherichia coli cyn operon: carbon dioxide-enhanced degradation of carbonic anhydrase." J Bacteriol 176(18);5711-7. PMID: 8083164

Lamblin94: Lamblin AF, Fuchs JA (1994). "Functional analysis of the Escherichia coli K-12 cyn operon transcriptional regulation." J Bacteriol 176(21);6613-22. PMID: 7961413

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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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