EXPRESSION OF THE HUMAN UDP-GLUCURONOSYLTRANSFERASE UGT1-ASTERISK-G IN ESCHERICHIA-COLI - INFLUENCE OF BACTERIAL SIGNAL PEPTIDES ON THE PRODUCTION AND LOCALIZATION OF THE RECOMBINANT PROTEIN

The membrane-bound human liver UDP-glucuronosyltransferase UGT16 was expressed in Escherichia coli. Exchange of the natural signal peptide by the bacterial signal peptides of pelB or OmpT proteins considerably increased the level of expression and, as the natural signal peptide, targeted the protein to the membranes. The extent of maturation of (s )pe1B-UGT16 precursor was about 30%. No processing of (s)OmpT-UGT1*6 occurred but the processing rate of this precursor could be significan tly increased by mutagenesis of the first two amino acid residues of t he mature sequence. These expression vectors allowed us to produce hig h levels of recombinant mature UGT16 required for further structural studies.