Viruses’ tricks for hijacking bacteria could inspire new antibiotics

By Sam Wong

In the quest to devise molecules that tamper with bacteria, the pharmaceutical industry is some way off the pace set by nature's experts. Some specialised viruses have been running their own drug screening programme for millions of years.

Many of these viruses employ elegant strategies to sabotage their bacterial hosts in order to exist and reproduce. So for scientists aiming to design better antibiotics, it's natural that viruses that infect bacteria should provide inspiration.

Researchers at Imperial College London have published the first detailed description of how a small molecule produced by a virus enables it to hijack bacteria's cellular equipment. The findings, published in Molecular Cell, provide a platform for the development of new drugs to fight infections.

An important target in bacteria for manipulation by these specialised viruses, called phages, is RNA polymerase. This essential enzyme enables the instructions encoded in the bacteria's genes to be read and turned into proteins.

A phage, called T7, infects the bacteria Escherichia coli and produces a small protein that subverts the normal workings of RNA polymerase in order to facilitate its own replication. Now Dr Sivaramesh Wigneshweraraj from the department of medicine and professor Steve Matthews from the department of life sciences have discovered how this protein, called Gp2, interacts with the bacterial enzyme to stop it from functioning.