Adam33 structure and phylogeny (A) Location and orientation of genes on BAC389B9. The entire Adam33 gene is contained within a 48 kb contig (AF155960) that also contains the Gfra4 gene and the 3' ends of Atrn and Sn. (B) Beginning with the translational start site, Adam33 is contained within 22 exons that span approximately 12.6 kb of genomic sequence. The putative signal sequence cleavage site (arrow), metalloprotease domain (asterisks) and transmembrane domain (line) are indicated. (C) ClustalW Phylogeny for ADAM proteins most closely related to Adam33 (arrow). For reference, human (Homo), mouse (Mus), and Xenopus laevis (Xen.) orthologs are shown for Adam9 and Adam22.