ISOLATION AND CHARACTERIZATION OF A MINI-COLLAGEN GENE ENCODING A NEMATOCYST CAPSULE PROTEIN FROM A REEF-BUILDING CORAL, ACROPORA-DONEI

Genomic and cDNA clones of a mcol gene encoding mini-collagen (MCOL), a nematocyst capsule protein, have been isolated from a reef-building coral, Acropora donei (Anthozoa). The gene and its flanking regions, c omprising 5382 bp and covering three exons and two introns, were seque nced, Exons 2 and 3 together have an open reading frame which can enco de a MCOL of 176 amino acids (aa), The coral MCOL has all the characte ristic regions present in the four hydra MCOL specified by the four mc ol cDNA clones previously isolated from Hydra magnipapillata (Hydrozoa ) by Kurz et al, [J, Cell Biol. 115 (1991) 1159-1169], including a cen tral Gly-Xaa-Yaa region and flanking Pro-rich and Cys-repeat regions, This observation suggests that a,mcol family is highly conserved in An thozoa and Hydrozoa, and also that the characteristic regions present in MCOL are essential for the structure and function of these peptides .