6TUP

Cryo-EM structure of Pf4 bacteriophage coat protein with single-stranded DNA

Summary for 6TUP

• Entry DOI: 10.2210/pdb6tup/pdb
• EMDB information: 10593
• Descriptor: Coat protein B of bacteriophage Pf1, DNA (5'-D(P*AP*AP*AP*AP*AP*A)-3') (2 entities in total)
• Functional Keywords: bacteriophage, helical, filamentous, virus
• Biological source: Pseudomonas virus Pf1; More
• Total number of polymer chains: 2
• Total formula weight: 6446.68

Authors

Tarafder, A.K.,von Kugelgen, A.,Bharat, T.A.M. (deposition date: 2020-01-08, release date: 2020-02-26, Last modification date: 2024-05-22)

Primary citation

Tarafder, A.K.,von Kugelgen, A.,Mellul, A.J.,Schulze, U.,Aarts, D.G.A.L.,Bharat, T.A.M.
Phage liquid crystalline droplets form occlusive sheaths that encapsulate and protect infectious rod-shaped bacteria.
Proc.Natl.Acad.Sci.USA, 117:4724-4731, 2020

PubMed Abstract: The opportunistic pathogen is a major cause of antibiotic-tolerant infections in humans. evades antibiotics in bacterial biofilms by up-regulating expression of a symbiotic filamentous inoviral prophage, Pf4. We investigated the mechanism of phage-mediated antibiotic tolerance using biochemical reconstitution combined with structural biology and high-resolution cellular imaging. We resolved electron cryomicroscopy atomic structures of Pf4 with and without its linear single-stranded DNA genome, and studied Pf4 assembly into liquid crystalline droplets using optical microscopy and electron cryotomography. By biochemically replicating conditions necessary for antibiotic protection, we found that phage liquid crystalline droplets form phase-separated occlusive compartments around rod-shaped bacteria leading to increased bacterial survival. Encapsulation by these compartments was observed even when inanimate colloidal rods were used to mimic rod-shaped bacteria, suggesting that shape and size complementarity profoundly influences the process. Filamentous inoviruses are pervasive across prokaryotes, and in particular, several Gram-negative bacterial pathogens including , and harbor these prophages. We propose that biophysical occlusion mediated by secreted filamentous molecules such as Pf4 may be a general strategy of bacterial survival in harsh environments.

PubMed: 32071243
DOI: 10.1073/pnas.1917726117

Experimental method

ELECTRON MICROSCOPY (3.2 Å)