What is it about?

Bacteria contain an enzyme called DNA gyrase. Its job is to coil up (or "supercoil") the DNA of the bacteria. The enzyme works like a tiny machine and during its reaction with the DNA it has to cut the DNA before later sticking it back together again. This is an Achilles heel for the bacteria as cut DNA can be lethal. Indeed, some widely used antibacterial drugs work by stopping gyrase from resealing the DNA. Without coherent DNA, the cells die. Unfortunately bacteria have developed strategies to resist the effects of these drugs. One such strategy involves proteins called pentapeptide repeat proteins (PRPs) which "rescue" DNA gyrase from the drugs. It is important to know how the PRPs do this so that we can design strategies to overcome the resistance. In this work we uncovered vital information informing us how PRPs work. The answer is fascinating - the proteins actually seem to mimic the DNA that the enzyme binds to and somehow use this ability to decrease the effectiveness of drugs.

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Why is it important?

Bacterial resistance to drugs is a growing problem and is expected to claim many lives in the future. Resistance mediated by PRPs is one of many strategies bacteria use. By contributing to our understanding of resistance we hope to contribute to the ongoing fight against drug resistant bacteria.


I have been working on DNA gyrase on and off for many years and had first had the idea of how PRPs could work over five years ago so it was gratifying to see experimental evidence supporting some of my theories!

Professor Jonathan Gardiner Heddle
Jagiellonian University

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This page is a summary of: Pentapeptide repeat protein QnrB1 requires ATP hydrolysis to rejuvenate poisoned gyrase complexes, Nucleic Acids Research, January 2021, Oxford University Press (OUP), DOI: 10.1093/nar/gkaa1266.
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