THE GLYOXYSOMAL 3-KETOACYL-COA THIOLASE PRECURSOR FROM BRASSICA-NAPUSHAS ENZYMATIC-ACTIVITY WHEN SYNTHESIZED IN ESCHERICHIA-COLI

Glyoxysomal 3-ketoacyl-CoA thiolase is the last enzyme in the beta-oxi dation of fatty acids in plant glyoxysomes. A full-length cDNA of the glyoxysomal 3-ketoacyl-CoA thiolase from Brassica napus and a truncate d version, lacking the N-terminal targeting signal were cloned in a T7 promoter-based vector, Both recombinant proteins were expressed in Es cherichia coli and activity was measured, Full-length and truncated 3- ketoacyl-CoA thiolase have comparable activity in E. coli. Moreover, f ull-length 3-ketoacyl-CoA thiolase was purified from E. coli and N-ter minal sequencing of the protein confirmed that the precursor form inde ed is enzymatically active. (C) 1997 Federation of European Biochemica l Societies.