FIG. 3.
Recombinant plasmid pYA3494 for PspA expression. (A) The PspA region used in this study. Functional domains of native PspA from S. pneumoniae (PspARx1) are diagramed. Dotted box, leader sequence (31 amino acids [aa]); open box, immunodominant α-helical region (aa 1 to 288); hatched box, proline-rich region (aa 289 to 370); 10 gray boxes, choline-binding repeats (aa 371 to 571); black box, C terminus (aa 572 to 588). Dotted lines represent the limit of the rPspA region used in this study. Bioinformatical analyses of the rPspA for antigenic index and surface probability are presented. Analyses were performed with the Protean module of the Lasergene sequence analysis software. (B) Map of recombinant plasmid pYA3494. A 0.7-kb EcoRI-HindIII fragment of PCR-amplified DNA of pspARx1 was cloned into the EcoRI and HindIII sites of pYA3493 (Fig. 2B). The cloned fragment included the immunogenic α-helical region of PspA including amino acids 3 through 257 of mature PspA (255 amino acids).