title: Expression and processing of bacterial beta-lactamase in the yeast Saccharomyces cerevisiae.
abstract: The mode of expression in Saccharomyces cerevisiae of the bacterial antibiotic resistance gene coding for beta-lactamase (EC 3.5.2.6) is described. Yeast transformants, containing hybrid plasmid pMP78-1 consisting of pBR325 in a 2-micrometers DNA vector, synthesize an active beta-lactamase protein. The enzyme was purified about 100-fold over crude extracts. With regard to activity, molecular weight, and binding to specific antibodies the yeast beta-lactamase was indistinguishable from the purified enzyme from Escherichia coli. Because the bacterial enzyme is synthesized as a preprotein with subsequent maturation, the results suggest that S. cerevisiae is able to convert the preprotein to the mature beta-lactamase. This was confirmed by in vitro experiments showing that the bacterial preprotein can be processed by crude extracts of S. cerevisiae.
mesh_terms: D004274:DNA, Recombinant; D004926:Escherichia coli / Q000235:genetics*; D005786:Gene Expression Regulation; D010957:Plasmids; D011498:Protein Precursors / Q000235:genetics; D012441:Saccharomyces cerevisiae / Q000235:genetics*; D014170:Transformation, Genetic; D001618:beta-Lactamases / Q000235:genetics*
chemical_list: D004274:DNA, Recombinant; D011498:Protein Precursors; D001618:beta-Lactamases