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Bacteria can protect themselves from viruses with the help of their clustered, regularly-interspaced short palindromic repeats (CRISPRs). These are vital in helping recent advancements in genetic modification, according to a team of Montana State University microbiologists.

"Bacteria get viral infections just like humans do," Blake Wiedenheft, coauthor of the paper, said in a press release. "Recently, we discovered that bacteria have sophisticated immune systems, called CRISPRs, and our work aims to understand how these immune systems work."

How CRISPRs separate virus DNA from its genetic material, enabling it to fight off the virus but not damage the host cell with its anti-viral measures was the subject of the study published in the Feb. 10 issue of Nature.

"Targeting the foreign DNA stored in the bacterial genome would result in an auto-immune reaction that would kill or at least make the bacteria very sick," Wiedenheft said. "The work in this paper explains how the immune system in 'Escherichia coli' differentiates between the bacteria's own genetic material and that of the virus."

With the help of X-ray crystallography, the team created a blueprint of the immune systems' surveillance system, analysising foreign DNA.

"These blueprints, which are conceptually similar to a builder's blueprint, explain how these biological machines work," Wiedenheft said. "We are now trying to use these blueprints to engineer this system for novel applications that Mother Nature never expected."

Hence, by grasping the processes in bacteria the CRISPR systems in human medicine and biotechnology can be used, which would enable scientists to cut and treat DNA more effectively.

"CRISPR systems have now been moved into human cells, and we can now program these systems to cut out and repair defective DNA in human cells," Wiedenheft concluded.