Enhancing and initiating phage-based therapies.

Drug development has typically been a primary foundation of strategy for systematic, long-range management of pathogenic cells. However, drug development is limited in speed and flexibility when response is needed to changes in pathogenic cells, especially changes that produce drug-resistance. The high replication speed and high diversity of phages are potentially useful for increasing both response speed and response flexibility when changes occur in either drug resistance or other aspects of pathogenic cells.

Three-dimensional architecture of the rod sensory cilium and its disruption in retinal neurodegeneration.

Defects in primary cilia lead to devastating disease because of their roles in sensation and developmental signaling but much is unknown about ciliary structure and mechanisms of their formation and maintenance. We used cryo-electron tomography to obtain 3D maps of the connecting cilium and adjacent cellular structures of a modified primary cilium, the rod outer segment, from wild-type and genetically defective mice. The results reveal the molecular architecture of the cilium and provide insights into protein functions.

Visualizing the structural changes of bacteriophage Epsilon15 and its Salmonella host during infection.

The efficient mechanism by which double-stranded DNA bacteriophages deliver their chromosome across the outer membrane, cell wall, and inner membrane of Gram-negative bacteria remains obscure. Advances in single-particle electron cryomicroscopy have recently revealed details of the organization of the DNA injection apparatus within the mature virion for various bacteriophages, including epsilon15 (ɛ15) and P-SSP7. We have used electron cryotomography and three-dimensional subvolume averaging to capture snapshots of ɛ15 infecting its host Salmonella anatum.

Modular software platform for low-dose electron microscopy and tomography.

Transmission electron microscopy imaging protocols required by structural scientists vary widely and can be laborious without tailor-made applications. We present here the jeol automated microscopy expert system (james) api integrator, a programming library for computer control of transmission electron microscopy operations and equipment. james has been implemented on JEOL microscopes with Gatan CCDs but is designed to be modular so it can be adapted to run on different microscopes and detectors.

Electron cryotomography reveals the portal in the herpesvirus capsid.

Herpes simplex virus type 1 is a human pathogen responsible for a range of illnesses from cold sores to encephalitis. The icosahedral capsid has a portal at one fivefold vertex which, by analogy to portal-containing phages, is believed to mediate genome entry and exit. We used electron cryotomography to determine the structure of capsids lacking pentons.