The human granzyme A (HFSP, CTLA3) gene maps to 5q11-q12 and defines a new locus of the serine protease superfamily.

Human granzyme A (HFSP, Hanukah factor serine protease; CTLA3, cytotoxic T-lymphocyte-associated serine esterase-3), a homodimeric, trypsin-like serine protease of 60 kDa found in granules of cytolytic T cells and natural killer cells, is implicated in lymphocyte-mediated target cell lysis. It contributes to DNA fragmentation in perforin (PRF1)-lysed target cells through an unknown mechanism. We have isolated a cosmid clone for the functional gene of human granzyme A and established its complete exon-intron map of 10 kb. Using an 11-kb subfragment of the cloned genomic DNA as a probe, we have identified the chromosomal position of human granzyme A on 5q11-q12. Thus, the human granzyme A gene falls into a region of homology between human chromosome 5 and mouse chromosome 13, band D, where the mouse granzyme A gene has been located previously. The granzyme A gene is not linked to known members of the large superfamily of serine proteases.