title: Characterization of muconate and chloromuconate cycloisomerase from Rhodococcus erythropolis 1CP: indications for functionally convergent evolution among bacterial cycloisomerases.
abstract: Muconate cycloisomerase (EC 5.5.1.1) and chloromuconate cycloisomerase (EC 5.5.1.7) were purified from extracts of Rhodococcus erythropolis 1CP cells grown with benzoate or 4-chlorophenol, respectively. Both enzymes discriminated between the two possible directions of 2-chloro-cis, cis-muconate cycloisomerization and converted this substrate to 5-chloromuconolactone as the only product. In contrast to chloromuconate cycloisomerases of gram-negative bacteria, the corresponding R. erythropolis enzyme is unable to catalyze elimination of chloride from (+)-5-chloromuconolactone. Moreover, in being unable to convert (+)-2-chloromuconolactone, the two cycloisomerases of R. erythropolis 1CP differ significantly from the known muconate and chloromuconate cycloisomerases of gram-negative strains. The catalytic properties indicate that efficient cycloisomerization of 3-chloro- and 2,4-dichloro-cis,cis-muconate might have evolved independently among gram-positive and gram-negative bacteria.
authors.affiliation: Institut für Mikrobiologie, Universität Stuttgart, Germany.
authors.forename: I P
authors.initials: IP
authors.lastname: Solyanikova
authors.forename: O V
authors.initials: OV
authors.lastname: Maltseva
authors.forename: M D
authors.initials: MD
authors.lastname: Vollmer
authors.forename: L A
authors.initials: LA
authors.lastname: Golovleva
authors.forename: M
authors.initials: M
authors.lastname: Schlömann
mesh_terms: D015107:4-Butyrolactone / Q000031:analogs & derivatives / Q000378:metabolism; D000272:Adipates / Q000378:metabolism; D000595:Amino Acid Sequence; D001565:Benzoates / Q000378:metabolism; D019817:Benzoic Acid; D001673:Biodegradation, Environmental; D002733:Chlorophenols / Q000378:metabolism; D019753:Intramolecular Lyases; D007535:Isomerases / Q000302:isolation & purification / Q000378:metabolism*; D008969:Molecular Sequence Data; D012240:Rhodococcus / Q000201:enzymology*; D013011:Sorbic Acid / Q000031:analogs & derivatives* / Q000378:metabolism; D013045:Species Specificity; D013379:Substrate Specificity
chemical_list: D000272:Adipates; D001565:Benzoates; D002733:Chlorophenols; C088142:5-chloromuconolactone; C088140:2-chloromuconic acid; C005939:muconic acid; C088141:2-chloromuconolactone; D019817:Benzoic Acid; D007535:Isomerases; D019753:Intramolecular Lyases; C021811:muconate cycloisomerase; C055773:chloromuconate cycloisomerase; D015107:4-Butyrolactone; D013011:Sorbic Acid