Viral interference of the bacterial RNA metabolism machinery

Abstract

In a recent publication, we reported a unique interaction between a protein encoded by the giant myovirus phiKZ and the Pseudomonas aeruginosa RNA degradosome. Crystallography, site-directed mutagenesis and interactomics approaches revealed this 'degradosome interacting protein' or Dip, to adopt an 'open-claw' dimeric structure that presents acidic patches on its outer surface which hijack 2 conserved RNA binding sites on the scaffold domain of the RNase E component of the RNA degradosome. This interaction prevents substrate RNAs from being bound and degraded by the RNA degradosome during the virus infection cycle. In this commentary, we provide a perspective into the biological role of Dip, its structural analysis and its mysterious evolutionary origin, and we suggest some therapeutic and biotechnological applications of this distinctive viral protein.

Keywords: Bacteriophage; Pseudomonas aeruginosa; RNA degradosome; RNase E; phage-host interaction.

Figure 1.

Displacement of RNA from the RNase E scaffold domain by Dip. (A) global composition of the P. aeruginosa RNA degradosome as observed in pull down assays. In the absence of Dip, RNA (dotted line) is bound by the RNase E scaffold domain and degraded by the catalytic domain. (B) When Dip is present, the RNase E scaffold domain is hijacked and RNA is no longer degraded.