The gene encoding the human puromycin-sensitive aminopeptidase (PSA) has be
en cloned and characterized. The human PSA gene is composed of 23 exons and
22 introns and spans approximately 40 kb of chromosome 17 at the interval
17q12-21, An analysis of the 5' end of the human PSA transcript reveals tha
t the translational start site corresponds to nt 210 of the human PSA cDNA,
as suggested by RT-PCR, 5' RACE, and computer analysis of expressed sequen
ce tags. A comparison of the exon/exon boundaries of the human PSA gene wit
h those of the human aminopeptidase N (APN) gene shows little conservation,
suggesting that the two genes, which are closely related in protein sequen
ce, diverged early during evolution. (C) 1999 Academic Press.