Type VII Secretion: A Highly Versatile Secretion System

• DOI: 10.1128/microbiolspec.vmbf-0011-2015
• Publication Date: 2016-04-09T01:37:48Z
• Authors: Louis S. Ates; Edith N. G. Houben; Wilbert Bitter
• Keywords: Cell envelope; Chaperone (clinical); Pathogenic bacteria

Type VII secretion (T7S) systems of mycobacteria secrete substrates over the unusual diderm cell envelope. Furthermore, T7S gene clusters are present throughout phylum Actinobacteria, and functional T7S-like have been identified in Firmicutes. Most can be divided into two families: Esx proteins, which found both Firmicutes PE PPE more mycobacterium-specific. Members families shown to secreted as folded heterodimers, suggesting that this is a conserved feature substrates. knowledge mechanism roles virulence comes from studies pathogenic mycobacteria. These bacteria contain up five systems, called ESX-1 ESX-5, each having its own role bacterial physiology virulence. In article, we discuss general composition individual components secretion. include membrane proteins with (predicted) enzymatic activities: predicted ATPase (EccC), likely required for energy provision T7S, subtilisin-like protease (MycP) involved processing specific Additionally, describe intracellular chaperone substrate recognition, based on recently published crystal structures molecular analysis. Finally, system-specific features different their pathogenesis provide an overview other bacteria.