Structural and functional studies of proteins from integrative conjugative elements

• Grant number: 25/04946-3
• Support Opportunities: Scholarships in Brazil - Doctorate
• Start date: May 01, 2025
• End date: April 30, 2029
• Field of knowledge: Biological Sciences - Biochemistry - Biochemistry of Microorganisms
• Principal Investigator: Marcio Vinicius Bertacine Dias
• Grantee: Cleiton Jesus Andrade Pereira
• Host Institution: Instituto de Ciências Biomédicas (ICB). Universidade de São Paulo (USP). São Paulo , SP, Brazil
• Associated research grant: 21/10577-0 - Biology of Bacteria and Bacteriophages Research Center, AP.CEPID

Abstract

Integrative Conjugative Elements (ICEs) are crucial mobile genetic elements for horizontal gene transfer (HGT). Incorporated into genomic DNA and replicated alongside the bacterial chromosome, ICEs differ from other genomic islands due to their ability to excise and integrate into recipient bacterial genomes through conjugation. These elements are widely distributed among bacterial species, particularly Gram-negative ones, and often harbor genes encoding antimicrobial resistance (AMR) and heavy metal tolerance. With the rising concern over AMR, ICEs have garnered increased scientific attention, having been previously overshadowed by plasmids. Among ICE families, SXT/R391 is the most studied due to its conserved essential genes involved in conjugation, integration, and regulation.This project aims to structurally and functionally characterize the TraI and MobI proteins, which play key roles in relaxosome formation and genetic transfer. We will employ genetic recombination techniques to disrupt these genes and analyze bacterial phenotypes. Additionally, we will use crystallography and cryo-electron microscopy to determine their structures, as they lack orthologs in other genetic elements. In vitro and in vivo experiments will validate their roles in conjugation and oriT recognition. Ultimately, we expect to contribute to understanding ICE transfer mechanisms and their role in AMR dissemination.