The peptidyl-prolyl isomerase SlrA contributes to virulence and adherence of Streptococcus pneumoniae

Streptococcus pneumoniae expresses two lipoproteins, which resemble homology with distinct families of peptidyl-prolyl isomerases (PPIases). The PpmA protein is homologous with the parvulin family of PPIases, whereas the streptococcal lipoprotein rotamase A (SlrA) resembles homology with the cyclophilins. In this study, we investigated the PPIase activity of SlrA and PpmA, and in particular the contribution of SlrA to virulence. SlrA clearly displayed PPIase activity, whereas PpmA did not show detectable PPIase activity. With respect to substrate specificity of SlrA, the largest kcat/KM was determined for the al…