Primary architecture and energy requirements of Type III and Type IV secretion systems

Elena Cabezón; Fernando Valenzuela-Gómez; Ignacio Arechaga

doi:10.3389/fcimb.2023.1255852

Primary architecture and energy requirements of Type III and Type IV secretion systems

Front Cell Infect Microbiol. 2023 Nov 27:13:1255852. doi: 10.3389/fcimb.2023.1255852. eCollection 2023.

Authors

Elena Cabezón¹, Fernando Valenzuela-Gómez¹, Ignacio Arechaga¹

Affiliation

¹ Departamento de Biología Molecular and Instituto de Biomedicina y Biotecnología de Cantabria (IBBTEC), Universidad de Cantabria- CSIC, Santander, Spain.

Abstract

Many pathogens use Type III and Type IV protein secretion systems to secrete virulence factors from the bacterial cytosol into host cells. These systems operate through a one-step mechanism. The secreted substrates (protein or nucleo-protein complexes in the case of Type IV conjugative systems) are guided to the base of the secretion channel, where they are directly delivered into the host cell in an ATP-dependent unfolded state. Despite the numerous disparities between these secretion systems, here we have focused on the structural and functional similarities between both systems. In particular, on the structural similarity shared by one of the main ATPases (EscN and VirD4 in Type III and Type IV secretion systems, respectively). Interestingly, these ATPases also exhibit a structural resemblance to F₁-ATPases, which suggests a common mechanism for substrate secretion. The correlation between structure and function of essential components in both systems can provide significant insights into the molecular mechanisms involved. This approach is of great interest in the pursuit of identifying inhibitors that can effectively target these systems.

Keywords: ATPases; T3SS; T4SS; bacterial conjugation; effector delivery.

Publication types

Review
Research Support, Non-U.S. Gov't

MeSH terms

Adenosine Triphosphatases
Bacteria / metabolism
Bacterial Proteins* / metabolism
Protein Transport
Type III Secretion Systems / metabolism
Type IV Secretion Systems* / metabolism

Substances

Type IV Secretion Systems
Bacterial Proteins
Adenosine Triphosphatases
Type III Secretion Systems

Grants and funding

The author(s) declare financial support was received for the research, authorship, and/or publication of this article. This work was supported by the Spanish Ministerio de Ciencia e Innovación Grant PID2019-104251GB-I00.