Structural and functional studies of the bacteria-phage interface by cryoelectron tomography

• Grant number: 24/14944-5
• Support Opportunities: Scholarships in Brazil - Doctorate (Direct)
• Start date: February 01, 2025
• End date: January 31, 2029
• Field of knowledge: Biological Sciences - Microbiology
• Principal Investigator: Germán Gustavo Sgro
• Grantee: Guilherme Oliveira Silva
• Host Institution: Faculdade de Ciências Farmacêuticas de Ribeirão Preto (FCFRP). Universidade de São Paulo (USP). Ribeirão Preto , SP, Brazil
• Associated research grant: 22/03018-7 - Structural, molecular and functional characterization of bacteriophages associated with bacteria of medical and agricultural interest, AP.PNGP.PI

Abstract

Among the total viral population, bacteriophages (phages) are viruses that thrive by infecting bacteria. In recent decades, recognition of the roles and applications of phages has gained prominence, ushering in "The Third Era of Phages". The phage infection process is highly dynamic, especially the early steps involving adsorption and genome delivery, both critical steps for successful infection. However, inevitably, most biostructure visualization techniques tend to distance the target structure from its natural context and introduce artifacts into the samples. In this sense, cryoelectronic tomography (cryoET) emerges as an alternative, since vitrification methods allow the preservation of fine ultrastructures in a practically native state, enabling the study of conformations and interactions that are difficult to isolate or stabilize. Deciphering the molecular mechanisms underlying the cycles of infection and viral replication is essential for devising ways to control the infection or predict its effects. As new phage models are discovered, several particularities are described, expanding the knowledge about so-called consolidated processes. Therefore, based on its relevance, this project aims to apply cryoET to study the processes involved in infection mainly by ¿M4-11 and ZC03 (podovirus) and, eventually, also by ZC01 (siphovirus) and LafX (myovirus), all modern lytic phages against Xanthomonas citri or Pseudomonas aeruginosa, both bacterial strains of great relevance in agriculture and medicine, respectively.