ROLE OF THE GENE ENCODING LIPASE ACTIVATOR FROM PSEUDOMONAS SP STRAINKWI-56 IN IN-VITRO ACTIVATION OF LIPASE

The function of the gene, act, which encodes lipase activator and that is downstream from the gene that encodes Lipase, lip, in Pseudomonas sp. strain KWI-56, was studied with Escherichia coli as the host organ ism. E. coli carrying both the lip and act genes in either cis or tran s produced an active lipase, but E. coli carrying only the lip gene pr oduced an equal amount of inactive lipase protein. The active and inac tive lipases had the same molecular weight and the same N-terminal ami no acid sequence, so their primary structures were the same. The inact ive lipase was not activated spontaneously, but it was activated in vi tro by the addition of a crude cell extract of E. coli carrying an exp ression plasmid of the act gene. Lipase from Pseudomonas sp. strain KW I-56 was completely without enzymatic activity when denatured, but reg ained activity in vitro upon addition of the crude cell extract. These results indicate that the act gene affects the activation involved in the conformational change of the lipase protein to its active form.