Figure 1.

Schematic representation of the tca and tcd genetic loci with their respective products superimposed upon them. Similarly shaded areas indicate regions of similar amino acid sequences. Proteolytic cleavage sites are indicated by arrowheads. Peptides which have been determined to occur in the mature Tca and Tcd complexes are labeled in red italics (Bowen et al., 1998; Guo et al., 1999).