Structure of defense against restriction proteins DarA and Hdf in phage P1 reveals a new molecular mechanism during phage assembly, infection and DNA ejection.

ABSTRACT: The continuous "arms race" between bacterial antiviral defense systems and phage anti-defense strategies drives evolutionary innovation. Previous study indicated that the defense against restriction (Dar) proteins DarA and Hdf in myophage P1 are associated with the head morphogenesis. However, the structural information for these proteins was lacking, and the mechanisms by which they mediate head morphogenesis and protect phage DNA against bacterial defense systems remained poorly understood. Using cryo-electron microscopy (cryo-EM), we resolved the entire structures of extended P1 and contracted P1 with partial DNA, with the latter lacking the baseplate, as well as the head structure of contracted P1 without DNA. We identified the structural proteins for the P1, including the head, connec

SUBMITTER: Zheng J 

PROVIDER: S-EPMC12810830 | biostudies-literature | 2026 Jan

REPOSITORIES: biostudies-literature