Mycoplasma pathogens sneaking past our line of defense

October 31, 2018

New research reveals that Mycoplasma pathogens make DNA in a unique way that may protect them from our immune response. The result could provide new avenues to combat the pathogens that utilize this strategy. The study is published today in the scientific journal Nature.

Each time they divide, bacteria need to copy their entire DNA, the blueprint of the cell. Large amounts of the four different DNA building blocks have to be produced. The enzyme that makes the building blocks is called RNR (ribonucleotide reductase).

Because of its essential role, RNR has been intensely studied for over 50 years. During this time it has been observed that in all organisms, from humans to bacteria, RNR requires metal ions for function. One general strategy that our immune system uses to fight invading bacteria is to starve them of metals.

"We discovered a family of RNR proteins in Mycoplasma that does not need metals" says Vivek Srinivas, graduate student at the Department of Biochemistry and Biophysics, Stockholm University and one of the authors of the study.

In the study Metal-free ribonucleotide reduction powered by a DOPA radical in Mycoplasma pathogens, the researchers show that instead of using metals, this type of RNR uses a modified amino acid radical to initiate the chemical reaction. Radicals are molecules with an odd number of electrons, something that renders them very reactive.

Many of the bacteria that utilize this new group of RNR are mycoplasma pathogens that invade mucosal surfaces in the respiratory and genital tracts. It is possible that this extraordinary way to make DNA building blocks evolved so that the bacteria can survive and multiply despite a lack of metals.

"It is remarkable how evolution found an alternate chemical solution to this problem, something we didn't think was possible without metals. Of course, this also means that there may be new avenues to combat the pathogens that utilize this strategy", says Martin Högbom, professor at the Department of Biochemistry and Biophysics, Stockholm University, leader of the research project.
-end-
For further information

Martin Högbom, professor at the Department of Biochemistry and Biophysics, Stockholm University
Phone: +4670-413 28 06
Email: hogbom@dbb.su.se

About the study

Metal-free ribonucleotide reduction powered by a DOPA radical in Mycoplasma pathogens is a collaboration between researchers at Stockholm University, the Max Planck Institute in Mülheim, the Karolinska Institute, and the Australian National University in Canberra.

Link to the study: http://dx.doi.org/10.1038/s41586-018-0653-6

Stockholm University

Related Bacteria Articles from Brightsurf:

Siblings can also differ from one another in bacteria
A research team from the University of Tübingen and the German Center for Infection Research (DZIF) is investigating how pathogens influence the immune response of their host with genetic variation.

How bacteria fertilize soya
Soya and clover have their very own fertiliser factories in their roots, where bacteria manufacture ammonium, which is crucial for plant growth.

Bacteria might help other bacteria to tolerate antibiotics better
A new paper by the Dynamical Systems Biology lab at UPF shows that the response by bacteria to antibiotics may depend on other species of bacteria they live with, in such a way that some bacteria may make others more tolerant to antibiotics.

Two-faced bacteria
The gut microbiome, which is a collection of numerous beneficial bacteria species, is key to our overall well-being and good health.

Microcensus in bacteria
Bacillus subtilis can determine proportions of different groups within a mixed population.

Right beneath the skin we all have the same bacteria
In the dermis skin layer, the same bacteria are found across age and gender.

Bacteria must be 'stressed out' to divide
Bacterial cell division is controlled by both enzymatic activity and mechanical forces, which work together to control its timing and location, a new study from EPFL finds.

How bees live with bacteria
More than 90 percent of all bee species are not organized in colonies, but fight their way through life alone.

The bacteria building your baby
Australian researchers have laid to rest a longstanding controversy: is the womb sterile?

Hopping bacteria
Scientists have long known that key models of bacterial movement in real-world conditions are flawed.

Read More: Bacteria News and Bacteria Current Events
Brightsurf.com is a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for sites to earn advertising fees by advertising and linking to Amazon.com.