A CANDIDATE MARSUPIAL PRP GENE REVEALS 2 DOMAINS CONSERVED IN MAMMALIAN PRP PROTEINS

The normal function of the pathogenicity-related protein, PrP (or prio n protein), is unknown. To shed light on functionally important domain s, we have characterized a candidate marsupial PrP gene. The deduced m arsupial PrP has an overall identity of about 80% to eutherian PrP at the amino acid (aa) level, This similarity is not equally distributed and two regions (aa 118-142 and 177-223) are particularly highly conse rved. In contrast, a repeat region in the N-terminal half of the marsu pial PrP shows dipeptide inserts not described in other PrP. Another p articular feature of the marsupial gene is the lack of a continuous OR F on the antisense strand, as is found in most eutherian PI P. We prop ose that antisense ORFs found in other species are artefactual. Compar ison with all known PrP argues that the molecule characterised is the true marsupial PrP orthologue.