Structural study of the VirB3/VirB4 homologous complex of the type IV secretion system of Staphylococcus aureus.

• Grant number: 24/15553-0
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: November 01, 2024
• End date: October 31, 2025
• Field of knowledge: Biological Sciences - Biochemistry - Chemistry of Macromolecules
• Principal Investigator: Cristiane Rodrigues Guzzo Carvalho
• Grantee: Julia Ferrareze D'Angelo Ferraz
• Host Institution: Instituto de Ciências Biomédicas (ICB). Universidade de São Paulo (USP). São Paulo , SP, Brazil

Abstract

Staphylococcus aureus is a Gram-positive pathogenic bacterium associated with various human infections, including pneumonia and bacteremia. It is notorious for its antibiotic resistance, complicating the treatment of diseases caused by this bacterium. The project focuses on the structure of proteins in the type IV secretion system (T4SS), an essential machinery for genetic transfer and the conjugation process that confers antibiotic resistance. Using the pGO1 plasmid from S. aureus, which harbors genes homologous to virB3 and virB4 in Gram-negative bacteria, the project aims to amplify, clone, and express the trsC, trsD, and trsE genes in Escherichia coli, a Gram-negative bacterium that has been extensively studied. Structural analysis by bioinformatics, comparison with E. coli models, and primer design were fundamental strategies. The study seeks to fill a gap in the structural knowledge of T4SS in Gram-positive bacteria, highlighting the importance of these systems in the dissemination of antibiotic resistance. Initial analyses clarify the molecular architecture of the TrsC, TrsD, and TrsE protein complex, while the effectiveness of the developed primers is crucial for advancing the cloning and expression steps. The project aims to contribute significantly to the understanding of T4SS in S. aureus, providing a solid foundation for future investigations and hypotheses in the field.