A distinct member of the aspartic proteinase gene family from the human malaria parasite Plasmodium falciparum

A gene (hap) transcribed during the intra-erythrocytic life cycle stages of the human malaria parasite Plasmodium falciparum was cloned and sequenced. It was found to encode a protein belonging to the aspartic proteinase fami ly but which carried replacements of catalytically crucial residues in the hallmark sequences contributing to the active site of this type of proteina se, Consideration is given as to whether this protein is the first known pa rasite equivalent of the pregnancy-associated glycoproteins that have been documented in ungulate mammals. Alternatively, it may be operative as a new type of proteinase with a distinct catalytic mechanism. In this event, sin ce no counterpart is known to exist in humans, it affords an attractive pot ential target against which to develop new anti-malarial drugs. (C) 1999 Fe deration of European Biochemical Societies.