With antibiotic resistance on the increase throughout the world, boffins at the University of York have made significant advance in understanding how bacteria use proteins to conduct a type of biological warfare, thus taking them a step closer to making a ‘smarter’ antibiotic.

The research team from the Department of Biology, led by Professor Colin Kleanthous, discovered a critical element in the mode of action of a class of colicins (so-called DNases)- protein antibiotics that are potent toxics used by bacteria like E. coli - that kill cells by destroying their DNA.

Professor Colin Kleanthous said that understanding how bacteria kill each other with protein toxins has brought boffins a step closer to developing ‘tailor-made’ antibiotics.

"Antibiotic resistance is on the increase throughout the world. Understanding how bacteria have evolved to kill each other with protein toxins might offer ways of constructing new, tailor-made antibiotics that target particular microorganisms," he said.

Though most proteins have a folded structure, DNase colicins are only partially so. The scientists found that the unfolded part of DNase colicin structure makes its way into an unsuspecting bacterium and blocks a key process that lowers the cell's defences and allows the toxin to enter.

Researchers are now trying to establish what it is about this blocking mechanism , christened 'competitive recruitment', that lowers the cells' defences toward the colicin.

The research is published in the latest edition of the Proceedings of the National Academy of Sciences (PNAS).