Virion structure and mechanism of genome delivery of bacteriophage SU10 from the family Podoviridae
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| Year of publication | 2021 |
| Type | Appeared in Conference without Proceedings |
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| Citation | |
| Description | Phages from the family Podoviridae use short non-contractile tails to deliver their genomes into bacteria. However, there is limited information on how the tails of Podoviridae phages penetrate cell walls of Gram-positive bacteria. Here we present the structures of virion and genome release intermediate of phage SU10. The virion of SU10 is formed by a prolate capsid with a tail decorated by long and short fibers. To infect cells SU10 binds to a cell surface by long tail fibers. Binding of short tail fibers to bacterial surface requires their rotation by 135°, which is connected to reorganization of tail proteins. In the new conformation, the short tail fibers and tail proteins form a 200 A long nozzle. We employed cryo-electron microscopy to visualize interactions of SU10 with E. coli cell wall. Attachment of short tail fibers to the cell surface forces the tail needle, which protrudes from the baseplate, through the outer membrane of the bacterial cell. The tail needle dissociates from the baseplate. Core proteins of SU10 with transglycosylase activity are ejected from the head to degrade cell wall peptidoglycan. Other core proteins form a translocation complex that extends the nozzle across the periplasm and inner membrane. The extended nozzle together with the attached translocation complex enable delivery of SU10 DNA into bacterial cytoplasm. |
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