Fig. 1. met-1 and met-2 gene structures, mutations and predicted protein structures. (A) The genomic structures of C. elegans met-1 and met-2. Exons are represented by black boxes, 3' untranslated regions by white boxes. The alternatively spliced exon six of met-1 is depicted as a white, stippled box. The locations of the deletion alleles are shown. (B) The domain structures of the MET-1 and MET-2 proteins.