DIENELACTONE HYDROLASE FROM RHODOCOCCUS-ERYTHROPOLIS-1-CP - PURIFICATION AND PROPERTIES

Dienelactone hydrolases (EC 3.1.1.45) have been shown to play an indis pensable role in the degradation of chloroaromatic compounds via ortho -cleavage of chlorocatechols. We report on the purification of dienela ctone hydrolase of the chlorophenol-utilizing strain Rhodococcus eryth ropolis 1CP to apparent homogeneity. Dienelactone hydrolase differed f rom the corresponding enzymes of other chloroaromatic compound-catabol izing strains in being restricted to substrates with a cis-dienelacton e structure. From the cis-dienelactone-hydrolyzing enzyme of a 4-fluor obenzoate-utilizing Burkholderia (Pseudomonas) cepacia strain, it diff ered considerably in properties such as pH optimum of activity, inhibi tion by p-chloromercuribenzoate, and amino acid composition. Thus, the re is not necessarily a close relationship between substrate specifici ty and other properties of dienelactone hydrolases.