SAMase of Bacteriophage T3 Inactivates Escherichia coli's Methionine S-Adenosyltransferase by Forming Heteropolymers.

ABSTRACT: S-Adenosylmethionine lyase (SAMase) of bacteriophage T3 degrades the intracellular SAM pools of the host Escherichia coli cells, thereby inactivating a crucial metabolite involved in a plethora of cellular functions, including DNA methylation. SAMase is the first viral protein expressed upon infection, and its activity prevents methylation of the T3 genome. Maintenance of the phage genome in a fully unmethylated state has a profound effect on the infection strategy. It allows T3 to shift from a lytic infection under normal growth conditions to a transient lysogenic infection under glucose starvation. Using single-particle cryoelectron microscopy (cryo-EM) and biochemical assays, we demonstrate that SAMase performs its function by not only degrading SAM but also by interacting with a

SUBMITTER: Simon-Baram H 

PROVIDER: S-EPMC8406200 | biostudies-literature | 2021 Aug

REPOSITORIES: biostudies-literature