A) Schematic diagram showing processing of the protoxin to the mature forms of Bj-xtrIT-(His6) by the signal peptidase. (B) DNA and translated protein sequences of the Bj-xtrIT-(His6) pro-toxin gene sub-cloned into the pASK-IBA32 vector. Stop codons are represented by ‘-’. Sequences are shaded according to the diagram in part (A).