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At the Institute of Mathematical Problems of Biology, Russian Academy of Sciences, a group of scientists established the structure of a special transmembrane signaling system that is present in living organisms (anammox bacteria or eubacteria). Biologists from the University of Freiburg, the State Research University of Nijmegen, and the Fundamental Research Institute in Hamburg worked on a long-term study.
What is an anammox bacterium?
These eubacteria were discovered by scientists at the end of the 20th century and immediately found application. They are used to purify wastewater from nitrogen, which fertilizes rural lands. In the course of various studies, it was found that microorganisms are able to absorb salts of nitric acid and ammonium. Bacteria convert these particles into dinitrogen and hydrogen oxide, which are the main constituents of the atmosphere. Anammox bacteria digest even with small amounts of ammonium (no oxygen is required during the digestion process).
Scientists have figured out how the anammox bacterium finds its “target”
Eubacteria do not have sense organs, so it is not known how it finds its “target” in the environment. One of the important unresolved biological dilemmas is the question of how the signal is transmitted through the outer membrane of the cell. Scientists became interested in an unusual protein found in one anammox bacterium. The sequence of aminocarboxylic acids (AMA) contained an unusual combination of 2 parts. One of them was very similar to a transmembrane protein that penetrates through the cell membrane and transfers ammonium particles to the nucleus. The second part resembled histidine kinase, which is often present in systems of transmembrane signaling to the cell nucleus.
Researchers have found that a living organism finds its purpose through a chain of ordinal chemical and biological reactions. The molecule is signaled by histidine phosphorylation. The studied protein is divided into two equal parts:
- the first penetrates through the cell membrane;
- the second is a plastic two-component system.
Biologists have suggested that with the help of a two-component protein, a signal is transmitted to the nucleus about the presence of a chemical compound in the atmosphere. This assumption has been confirmed over time in numerous studies.
Other conclusions of scientists
The researchers argue that the eubacteria does not have a transport function, so it attaches to ammonium, as a result of which the configuration of the protein changes – it begins to move. Due to the connection with a polyatomic cation, a chemical-biological reaction occurs, which is a signal about the presence of a chemical compound in the atmosphere.
Biologists have tried to obtain the structure of a bacterium by exposing it to x-rays. They came to the conclusion that accurate data can be obtained by protein crystallization. In this process, a radical amplification of the rays is observed, the picture becomes clearer. When studying a bacterium, it was quite difficult to obtain high-quality crystals due to the flexible two-component protein. It was possible to study its structure in detail only after applying special mathematical methods developed by scientists from the Institute of Mathematical Problems of Biology.