Bacteria, like all living beings, defend themselves against infectious agents, in this case mainly viruses known as “phages”. The mechanisms are extremely diverse and vary from one bacterium to another. Many are not yet fully understood. Recent research showed that many of these systems involve proteins called “Reverse Transcriptases” (RTs). RTs are enzymes that manufacture DNA (where the genetic material is stored), using RNA, an intermediary between DNA and protein, as a template. By the end of 2021, more than 30 bacterial defence systems associated with these RTs had been described. In this project we focused on one of these systems, known as UG17. This system is found in bacteria of the genus Salmonella and Escherichia, among others, and is characterized by the fact that the RT is associated with another protein called SLATT, which is predicted to form pores in the membrane. Although their role in the defence mechanism is still unknown, we demonstrated that the protection of bacteria against infection by some phages requires the participation of both RT and SLATT.

Keywords: Defence systems; UG17; Reverse transcriptase; SLATT

Directed by: Francisco Martínez-Abarca Pastor