Sequence-based structural/motif and stereochemical analysis of enterococcal surface protein in endodontic

Area of Science:

• Microbiology
• Structural Biology
• Bioinformatics

Background:

• Enterococcus faecium synthesizes enterococcal surface protein (Esp), a cell wall-anchored adhesin.
• Esp is implicated in healthcare-associated infections and persistent root canal disease.
• Understanding Esp structure can aid in developing strategies to inhibit attachment and reduce biofilm formation.

Purpose of the Study:

• To perform an in silico characterization of Esp's secondary structure, conserved motifs, and stereochemical quality.
• To correlate these structural features with Esp's role in adhesion and biofilm persistence.

Main Methods:

• Sequence analysis using Garnier-Osguthorpe-Robson (GOR) for secondary structure prediction.
• Motif and feature annotation.
• Stereochemical evaluation using Ramachandran plots and G-factor analysis.

Main Results:

• Esp is predicted to have a predominantly beta-sheet structure with alpha-helices, turns, and beta-hairpins, resembling Ig-like modules.
• Stereochemical analysis indicates acceptable backbone geometry (85% favored Ramachandran regions, G-factor -0.33).
• Abundant turns and hairpins likely act as flexible linkers, promoting surface binding and biofilm stability under stress.

Conclusions:

• Sequence-based structural and stereochemical analyses suggest Esp possesses a flexible, beta-rich scaffold.
• Recurrent turns and hairpins in Esp may facilitate adhesion and biofilm persistence in endodontic environments.