Structure-Function Characterization of Streptococcus intermedius Surface Antigen Pas
Joshua L. Mieher, Norbert Schormann, Ren‐Chin Wu, Manisha Patel, Sangeetha Purushotham, Hui Wu, Jessica Scoffield, Champion Deivanayagam
Abstract
Streptococcus intermedius, an oral commensal bacterium, has been clinically observed in subgingival dental plaque, purulent infections, and cystic fibrosis lungs. In this study, we have (i) determined the crystal structure of the V and C regions of Pas; (ii) shown that its surface protein Pas adheres to fibrinogen, which could potentially ferry the microbe through the bloodstream from the oral cavity; (iii) characterized Pas's high-affinity adherence to lung alveolar protein Gp340 that could fixate the microbe on lung epithelial cells; and (iv) most importantly, shown that these surface proteins on the oral commensal S. intermedius enhance biofilms of known pathogens Candida albicans and Pseudomonas aeruginosa.