Functional characterization and molecular modelling of FnFgBP, a surface protein from Streptococcus agalactiae

摘要: Pneumococcal adherence and virulence factor A (PavA) were first identified in Streptococcus pneumoniae as an adhesin binding to fibronectin studies suggested that it is important determinant. Homologs of PavA are found many Gram-positive bacteria including S. agalactiae. However, date, the details its structure or mode interaction with host molecule(s) not known. To characterize identify ligand region GBS1263 agalactiae (ortholog PavA), two segments namely seg-N (residues 1–264) seg-C 265–551) was cloned expressed which resulted accumulation proteins inclusion bodies. Seg-N solubilised using urea subsequently refolded purified. Circular dichroism secondary prediction indicated both predominantly consist helices. Molecular modelling also supports this data. Sequence comparison these a previously characterized (Fn)/fibrinogen (Fg) protein, FBP54 from pyogenes showed residues 77–165 have 81% similarity Fn/Fg whereas has no significant similarity. Binding assays (dot blot, western blot ELISA) biolayer interferometry binds Fn Fg only Fg. The present study could be dual-ligand adhesin, different regions. This property analogous aureus FnBPA modules. Based on property, we termed FnFgBP (fibronectin/fibrinogen protein).