PROPIONIBACTERIUM-ACNES, A RESIDENT OF LIPID-RICH HUMAN SKIN, PRODUCES A 33 KDA EXTRACELLULAR LIPASE ENCODED BY GEHA

Five independent clones of the Propionibacterium acnes P-37 lipase gen e (gehA) were obtained in Escherichia coli, and the gene was localized to a 2.75 kb Xhol fragment by subcloning. The five clones were shown to contain the same gene by Southern blotting with a DIG-labelled prob e to gehA. The nucleotide sequence of gehA was determined, and shown t o contain a single ORF of 1017 kb, encoding a protein of 339 amino aci ds. The predicted molecular mass was 36 kDa. A 33 kDa (PAGE) radiolabe lled polypeptide was detected from E. coli minicell preparations harbo uring gehA, which could correspond to GehA after cleavage of the putat ive 26 amino acid residue signal peptide. gehA was overexpressed in E. coli under the control of the bacteriophage T7 promoter, and the corr esponding polypeptide was found to be present in insoluble aggregates. Active lipase was produced when the overexpressing strain was incubat ed at a reduced temperature in the presence of sucrose. Purification o f lipase from P. acnes culture supernatant fluids confirmed the produc tion of a 33 kDa (PAGE) lipase.