A Bacteriophage DNA Mimic Protein Employs a Non-specific Strategy to Inhibit the Bacterial RNA Polymerase.

Jia Ma,Zhihao Wang,Hongliang Wang,Steve Matthews,Sivaramesh Wigneshweraraj,Maximo Sanz-Hernandez,Yawen Wang,Nancy Mulvenna,Bing Liu,Yanqing Li,Peipei Zhang

doi:10.3389/fmicb.2021.692512

Abstract

DNA mimicry by proteins is a strategy that employed by some proteins to occupy the binding sites of the DNA-binding proteins and deny further access to these sites by DNA. Such proteins have been found in bacteriophage, eukaryotic virus, prokaryotic, and eukaryotic cells to imitate non-coding functions of DNA. Here, we report another phage protein Gp44 from bacteriophage SPO1 of Bacillus subtilis, employing mimicry as part of unusual strategy to inhibit host RNA polymerase. Consisting of three simple domains, Gp44 contains a DNA binding motif, a flexible DNA mimic domain and a random-coiled domain. Gp44 is able to anchor to host genome and interact bacterial RNA polymerase via the β and β′ subunit, resulting in bacterial growth inhibition. Our findings represent a non-specific strategy that SPO1 phage uses to target different bacterial transcription machinery regardless of the structural variations of RNA polymerases. This feature may have potential applications like generation of genetic engineered phages with Gp44 gene incorporated used in phage therapy to target a range of bacterial hosts.

Highlights

Bacteriophages, or bacterial viruses, have evolved distinct mechanisms to take over various host biological processes for effective reproduction
We proposed a new model in which Gp44 interacts with β and β subunit of RNA polymerase (RNAP) to interfere with bacterial RNAP activity during SPO1 development
Gp44 Interacts With β and β Subunits of Both Escherichia coli and Bacillus subtilis RNAP

Summary

Introduction

Bacteriophages, or bacterial viruses, have evolved distinct mechanisms to take over various host biological processes for effective reproduction. Phage produces many proteins that interact with bacterial key enzymes to inhibit or modify related biological activities (Salmond and Fineran, 2015). RNA polymerase is the predominant target for the phage to utilize the bacterial transcription machinery in the early stage of invasion and to inhibit the host RNA polymerase activity in the later stages (Krupp, 1988). Understanding the molecular mechanisms of phage antibacterial proteins and their interactions with RNAP has inspired research into new antibacterial compounds or treatments for Gram-negative bacteria (Sunderland et al, 2017)

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