Organization of the gene encoding the human endothelin-converting enzyme (ECE-1).

The two human endothelin-converting enzyme (ECE-1) isoforms, which differ by their N-terminal region, are encoded by a single gene. The gene is composed of 19 exons that span more than 68 kilobases and has been mapped to the 1p36 band of the human genome. The two isoform mRNAs display different tissue distributions. Their precursors are transcribed from two distinct start sites, upstream from exon 1 and exon 3, respectively. Sequence analysis of the two putative promoters revealed the presence of motifs characteristic for several transcription factors. Comparison of the ECE-1 gene structure with those of other zinc metalloproteases, as well as a phylogenetic study, confirm the existence of a metalloprotease subfamily composed of ECE-1, ECE-2, neutral endopeptidase, Kell blood group protein, and two bacterial enzymes.