Figure 1

Schematic representation of DNA matrix and fragments amplified for mutant constructions. Black bars (F1 to F7) represent the fragments amplified from prtS, prtH, emR and aphA3 genes used to produce mutants expressing a PrtH fusion protein. Numbers refer to the last nucleotide of a domain (bold characters) or fragment limits (italic characters), starting from the adenosine nucleotide of the start codon of the ORF. The proteinase genes prtH (A) of Lactobacillus helveticus CNRZ32 CIRM-BIA 103 [this study,[28] and prtS (B) of Streptococcus thermophilus LMD-9 [this study,[25] are represented with their domains: upstream regions contain promoter and ribosome binding site (RBS), followed by S (signal sequence domain), PP (propeptide domain), PR (catalytic domain), A (A domain), B (B domain) in prtH, H (helix domain), W (cell-wall spacer domain) containing in prtH a 303 nucleotides S-layer attachment domain (small bar) and AN (anchor domain) in prtS with the LPNTG anchoring site. The downstream regions with the prtH and prtS terminator signals are also represented[22, 28]. The erythromycin resistance gene (emR) is presented in the pG+host9 plasmid (C) with its promoter (Prom) and its ORF[48]. The kanamycin resistance gene (aphA3) inserted in S. thermophilus LMD-9 TIL1193 chromosome (D) is presented with its promoter (Prom) and its ORF[18].