Domain Architecture and Functional Dynamics of Enterococcal Surface Protein (Esp) in Enterococcus faecium: Insights into Endodontic Virulence and Persistence

Abstract

Enterococcus faecium (E.f) is a durable pathogen often linked to persistent endodontic (root canal) infections. It frequently expressions strong resistance to ordinary treatments. The enterococcal surface protein (Esp), which start on the bacterial cell surface, is a key virulence factor. Esp contributes to biofilm formation, tissue attachment, & avoidance of the host immune system. This study presents a comprehensive in silico analysis of Esp, concentrating on its domain structure, physicochemical features, & its importance in endodontic infections.

Insilico analysis with InterProScan & SMART recognized more than a few structural domains within Esp. These include a YSIRK-type signal peptide, Rib domain, repetitive surface antigen motifs, bacterial immunoglobulin-like folds, & a C-terminal LPXTG anchor sequence. Collected, these domains suggest the most important roles in adhesion & host-pathogen interactions. 3-D structural modeling, created with AlphaFold & validated through Ramachandran plot valuation, presented a stable configuration. In total, 88.55% of residues were in energetically favored regions. Supplementary analyses covered hydropathy profiles, atomic & amino acid composition, & conserved motifs imperative for binding to the extracellular matrix & for bacterial persistence. These findings highlight the structural & functional importance of Esp in E. faecium disease. They suggest Esp could be a promising target for new therapies against difficult endodontic infections.