IntEnz

EC 4.5.1.2 - 3-chloro-D-alanine dehydrochlorinase

IntEnz Enzyme Nomenclature
EC 4.5.1.2

Names

Reactions

• (1) 3-chloro-D-alanine + H2O = pyruvate + chloride + NH3
•   (1a) 3-chloro-D-alanine = chloride + 2-aminoprop-2-enoate
•   (1b) 2-aminoprop-2-enoate = 2-iminopropanoate (spontaneous)
•   (1c) 2-iminopropanoate + H2O = pyruvate + NH3 (spontaneous)

Cofactor

• pyridoxal 5'-phosphate

Comments:

A pyridoxal-phosphate protein. The enzyme cleaves a carbon-chlorine bond, releasing a chloride and an unstable enamine product that tautomerizes to an imine form, which undergoes a hydrolytic deamination to form pyruvate and ammonia. The latter reaction, which can occur spontaneously, can also be catalysed by EC 3.5.99.10, 2-iminobutanoate/2-iminopropanoate deaminase. The enzyme's activity can also result in β-replacement reactions, e.g. in the presence of hydrogen sulfide it can convert 3-chloro-D-alanine into D-cysteine and chloride.

Links to other databases

References

1. Nagasawa, T., Ishii, T. and Yamada, H.
   Physiological comparison of D-cysteine desulfhydrase of Escherichia coli with 3-chloro-D-alanine dehydrochlorinase of Pseudomonas putida CR 1-1.
   Arch. Microbiol. 149 : 413-416 (1988). [PMID: 3132906]
2. Yamada, H., Nagasawa, T., Ohkishi, H., Kawakami, B. and Tani, Y.
   Synthesis of D-cysteine from 3-chloro-D-alanine and hydrogen sulfide by 3-chloro-D-alanine hydrogen chloride-lyase (deaminating) of Pseudomonas putida.
   Biochem. Biophys. Res. Commun. 100 : 1104-1110 (1981). [PMID: 6791643]

[EC 4.5.1.2 created 1984]