An extensive disulfide bond network prevents tail contraction in Agrobacterium tumefaciens phage Milano.

ABSTRACT: A contractile sheath and rigid tube assembly is a widespread apparatus used by bacteriophages, tailocins, and the bacterial type VI secretion system to penetrate cell membranes. In this mechanism, contraction of an external sheath powers the motion of an inner tube through the membrane. The structure, energetics, and mechanism of the machinery imply rigidity and straightness. The contractile tail of Agrobacterium tumefaciens bacteriophage Milano is flexible and bent to varying degrees, which sets it apart from other contractile tail-like systems. Here, we report structures of the Milano tail including the sheath-tube complex, baseplate, and putative receptor-binding proteins. The flexible-to-rigid transformation of the Milano tail upon contraction can be explained by unique electrostatic p

SUBMITTER: Sonani RR 

PROVIDER: S-EPMC10811340 | biostudies-literature | 2024 Jan

REPOSITORIES: biostudies-literature