IntEnz

EC 4.2.1.104 - Cyanase

IntEnz Enzyme Nomenclature
EC 4.2.1.104

Names

Reactions

• (1) cyanate + HCO3- + 2 H+ = NH3 + 2 CO2
•   (1a) cyanate + HCO3 + H+ = carbamate + CO2
•   (1b) carbamate + H+ = NH3 + CO2 (spontaneous)

Comments:

This enzyme, which is found in bacteria and plants, is used to decompose cyanate, which can be used as the sole source of nitrogen [6,7]. Reaction (1) can be considered as the reverse of 'carbamate = cyanate + H2O', where this is assisted by reaction with bicarbonate and carbon dioxide (see mechanism above) [2], and hence is classified in sub-subclass 4.2.1. Bicarbonate functions as a recycling substrate [2].

Links to other databases

References

1. Anderson, P.M.
   Purification and properties of the inducible enzyme cyanase.
   Biochemistry 19 : 2882-2888 (1980). [PMID: 6994799]
2. Johnson, W.V. and Anderson, P.M.
   Bicarbonate is a recycling substrate for cyanase.
   J. Biol. Chem. 262 : 9021-9025 (1987). [PMID: 3110153]
3. Taussig, A.
   The synthesis of the induced enzyme, "cyanase", in E. coli.
   Biochim. Biophys. Acta 44 : 510-519 (1960). [PMID: 13775509]
4. Taussig, A.
   Some properties of the induced enzyme cyanase.
   Can. J. Biochem. 43 : 1063-1069 (1965). [PMID: 5322950]
5. Anderson, P.M., Korte, J.J. and Holcomb, T.A.
   Reaction of the N-terminal methionine residues in cyanase with diethylpyrocarbonate.
   Biochemistry 33 : 14121-14125 (1994). [PMID: 7947823]
6. Kozliak, E.I., Fuchs, J.A., Guilloton, M.B. and Anderson, P.M.
   Role of bicarbonate/CO₂ in the inhibition of Escherichia coli growth by cyanate.
   J. Bacteriol. 177 : 3213-3219 (1995). [PMID: 7768821]
7. Walsh, M.A., Otwinowski, Z., Perrakis, A., Anderson, P.M. and Joachimiak, A.
   Structure of cyanase reveals that a novel dimeric and decameric arrangement of subunits is required for formation of the enzyme active site.
   Structure 8 : 505-514 (2000). [PMID: 10801492]

[EC 4.2.1.104 created 1972 as EC 3.5.5.3, transferred 1990 to EC 4.3.99.1, transferred 2001 to EC 4.2.1.104, modified 2007]