BACTERIAL ASPARTIC PROTEINASES

Regions of genomic DNA encoding putative aspartic proteinase domains w ere amplified by PCR from the bacterial species, Escherichia coli and Haemophilus influenzae. Expression of each of these DNA fragments resu lted in the accumulation of the corresponding recombinant proteins in insoluble aggregates, Each recombinant protein was solubilised, refold ed and shown to be able to cleave synthetic peptides that have been ex tensively used previously as substrates for aspartic proteinases of ve rtebrate, fungal and retroviral origin, Each activity was completely b locked by the diagnostic aspartic proteinase inhibitor, acetyl-pepstat in, This is thus the first report demonstrating unequivocally that asp artic proteinases may be present in bacteria. (C) 1997 Federation of E uropean Biochemical Societies.