The Type IVB secretion system: an enigmatic chimera
1Research Institute for Microbial Diseases, Osaka University, Yamadaoka 3-1, Suita, Osaka 565-0871, Japan.
Abstract:
Type IV secretion systems (T4SSs) are transporters that span the bacterial inner and outer membranes and deliver substrate biomolecules, including proteins and DNAs, into cells. Recent progress in structural analyses of conjugative plasmid-encoded type IVA secretion systems (T4ASSs) has revealed a unique molecular architecture. The essential virulence system, the Dot/Icm Type IVB secretion system (T4BSS) encoded by the intracellular bacterial pathogen Legionella pneumophila is distantly related to T4ASSs. Molecular and structural analyses of the Dot/Icm T4BSS have provided insights into the mechanisms of assembly and function. Here we highlight the chimeric quality of T4BSSs that possess components with similarity to many bacterial secretion systems.
More Related Videos
Related Concept Videos
Gram-negative Bacterial Protein Secretion Systems
Overview of Secretory Vesicles
Various proteins regulate the aggregation of molecules inside the secretory vesicles. Chromogranins...
Intralumenal Vesicles and Multivesicular Bodies
Insulin Secretory Vesicles
Bacterial Translocation and Protein Secretion
Exocrine Glands: Methods of Secretion
Merocrine Secretion
Merocrine secretion is the most common type of exocrine secretion. The secretions are enclosed in vesicles and moved to the cell's apical surface, where the contents are released by exocytosis. For example, mucous, a watery secretion rich in the glycoprotein mucin, is a merocrine secretion. The eccrine...


