CORRELATION OF THE EXON INTRON ORGANIZATION TO THE SECONDARY STRUCTURES OF THE PROTEASE DOMAIN OF MOUSE MEPRIN ALPHA-SUBUNIT/

Metalloendopeptidases of the astacin family contain a homologous prote ase domain of about 200 amino acids. We now report the genomic structu re corresponding to the protease domain for one member of this family, the mouse meprin alpha subunit. This is the first such description fo r the mammalian meprin subunits. It consists of four small exons (76 t o 222 base pairs) and three large introns (2.9 to 4.2 kilobases). The exon/intron organization correlates well with the secondary structure elements of the domain as predicted by computer modeling. Exon Ep1 con tains beta strand 1, and Ep2 consists of helix A and beta strands II-I II. Ep3 corresponds to beta strands IV-V and helix B. Ep4 correlates w ith helices C and D. Introns Ip1 and Ip2 are present at the beginning of helix A and beta strand IV, respectively, and Ip3 is between helice s B and C. Similar analyses of sequences previously published by other s, have extended this correlation to other astacin family members from different organisms. The relationship between gene and protein struct ures within the astacin family provide novel information on the evolut ion of this family in relation to other gene families. (C) 1997 Elsevi er Science B.V.