14.8 kb SalI-SpeI fragment, containing 8.7 kb genomic sequences upstream of the fj open reading frame (ORF), and 4.3 kb downstream sequences. Two predicted sites for signal peptidase cleavage in the ORF have been mutated (amino acid substitutions V87F and A91M), a third potential signal peptidase cleavage site predicted in the ORF is not mutated. This is expected to result in reduced or no cleavage of the expressed protein.