FIG. 2.

Asd⁺ antigen expression vectors. (A) Asd⁺ vector pYA3342. The map of pYA3342 and the nucleotide sequences of the P_trc promoter region and multicloning sites are shown. (B) Periplasmic secretion Asd⁺ vector pYA3493. A DNA fragment encoding the β-lactamase signal sequence and 12 amino acid residues of the N terminus of mature β-lactamase of plasmid pBR322 was positioned under the control of the P_trc promoter of the Asd⁺ vector pYA3342 (pBR ori). The map of pYA3493 and the nucleotide sequences of the P_trc promoter region, β-lactamase signal sequence (bla SS), and multicloning sites are shown. The P_trc sequences for −35, −10, and SD are indicated, and the translation start codon is in boldface. An arrow within the sequence indicates the signal peptidase cleavage site. Unique restriction enzyme sites in the multicloning site are indicated. 5ST1T2 is a transcriptional terminator.