Gino Cingolani, PhD, & Team use Cryo-EM to solve structure of the T7 DNA-Ejectosome (in Molecular Cell)
Bacterial viruses (or bacteriophages), the most abundant form of life on earth, are increasingly important biomedicines utilized in the clinics and food industry to eradicate antibiotic-resistant pathogens. Yet, little is known about how bacteriophages deliver DNA into bacteria. In this paper, a team of Jefferson researchers in the Cingolani lab, deciphered the first complete architecture of the bacteriophage T7 DNA-ejectosome.
Using a combination of bottom-up biochemical reconstitution and top-down cryogenic-electron microscopy (cryo-EM), the authors determined the first structure of a DNA-ejectosome at 2.7 Å resolution. This molecular machine forms a transient DNA channel, which is expelled into the bacterium cell envelope during infection to mediate genome delivery. Biochemical and evolutionary analysis suggests the DNA-ejectosome is conserved among short-tailed bacteriophages that infect gram-negative bacteria, including those used in the clinics for Phage Therapy.