CryoEM of bacterial secretion systems: A primer for microbiologists

CryoEM has come of age, enabling considerable structural insights into many facets of molecular biology. Here, we present a primer for microbiologists to understand the capabilities and limitations of two complementary cryoEM techniques for studying bacterial secretion systems. The first, single particle analysis, determines the structures of purified protein complexes to resolutions sufficient for molecular modeling, while the second, electron cryotomography and subtomogram averaging, tends to determine more modest resolution structures of protein complexes in intact cells. We illustrate these abilities with examples of insights provided into how secretion systems work by cryoEM, with a focus on type III secretion systems.

Automated summary

CryoEM has matured, offering valuable structural insights into molecular biology. This technique, through single particle analysis and electron cryotomography and subtomogram averaging, provides microbiologists with the ability to study bacterial secretion systems, particularly focusing on the type III secretion system.