The thiocarbamate-inducible Rhodococcus enzyme ThcF as a member of the family of α/β hydrolases with haloperoxidative side activity

Purified thiocarbamate-inducible ThcF of Rhodococcus erythropolis N186/21, overexpressed in Escherichia coli, displayed several characteristics of the HASH family of enzymes that groups prokaryotic proteins of the alp hydrolase superfamily possessing serine-dependent hydrolase and/or haloperoxidase activity. Kinetic analysis of bromination and ester hydrolysis revealed a low affinity of ThcF for model substrates. Sulfoxidation of thiocarbamates was demonstrated but probably represents a side activity due to peroxoacid generation by the enzyme. The thcF-linked thcG gene, encoding a LAL-type regulator, triggers expression of thcF in Rhodococcus. The tandem gene organization thcG-thcF is conserved in the thiocarbamate-degrading strain Rhodococcus sp. 1330. It is proposed that HASH enzymes may be involved in the metabolism of plant-derived compounds. (C) 2003 Federation of European Microbiological Societies. Published by Elsevier Science B.V. All rights reserved.