FIG. 4.

Site-specific mutations in BAR block P. gingivalis adherence to streptococci. Adherence of P. gingivalis to native SspB protein (●—●) and the site-specific mutants N/G¹¹⁸² (▪—▪), V/P¹¹⁸⁵ (⧫—⧫), and N/G¹¹⁸²: V/P¹¹⁸⁵ (▴—▴) was carried out as described previously for the synthetic peptides. Substitution of Pro for Val¹¹⁸⁵, alone or in combination with a mutation of Gly for Asn¹¹⁸², resulted in a sequence with a predicted secondary structure identical to that of SpaP. The substitution of Gly for Asn¹¹⁸² by itself is not predicted to induce a β-turn, but generates a putative α-helix extending to Ser¹¹⁹³. Error bars represent standard deviation, and all experiments were carried out in triplicate.