STRUCTURE OF THE GENE FOR PORCINE PEPTIDE ANTIBIOTIC PR-39, A CATHELIN GENE FAMILY MEMBER - COMPARATIVE MAPPING OF THE LOCUS FOR THE HUMAN PEPTIDE ANTIBIOTIC FALL-39

PR-39 is a porcine 39-aa peptide antibiotic composed of 49% proline an d 24% arginine, with an activity against Gram-negative bacteria compar able to that of tetracycline, In Escherichia coil, it inhibits DNA and protein synthesis, PR-39 was originally isolated from pig small intes tine, but subsequent cDNA cloning showed that the gene is expressed in the bone marrow, The open reading frame of the clone showed that PR-3 9 is made as 173-aa precursor whose proregion belongs to the cathelin family. The PR39 gene, which is rather compact and spans only 1784 bp has now been sequenced, The coding information is split into four exon s, The first exon contains the signal sequence of 29 residues and the first 37 residues of the cathelin propart. Exons 2 and 3 contain only cathelin information, while exon 4 codes for the four C-terminal cathe lin residues and the mature PR-39 peptide extended by three residues. The sequenced upstream region (1183 bp) contains four potential recogn ition sites for NF-IL6 and three for APRF, transcription factors known to regulate genes for both cytokines and acute phase response factors , Genomic hybridizations revealed a fairly high level of restriction f ragment length polymorphism and indicated that there are at least two copies of the PR39 gene in the pig genome, PR39 was mapped to pig chro mosome 13 by linkage and in situ hybridization mapping, The gene for t he human peptide antibiotic FALL-39 (also a member of the cathelin fam ily) was mapped to human chromosome 3, which is homologous to pig chro mosome 13.