Scientists fr om the NSU "Synthetic Biology" Strategic Academic Unit conducted a study on the behavior of DNA polymerases in a collision with "sewn together" DNA proteins. The results provide a foundation for the development of artificial DNA polymerases, which can be used for various purposes. One of the leading international interdisciplinary journals, “PLoS ONE”, published the work of these Novosibirsk scientists.
Many people probably remember a picture from their school biology textbook of a cell with a large interior ball, its core. DNA molecules are stored in the cellular nucleus wh ere information for constructing the human body are encoded. However, the nucleus not only contains DNA, it also possesses proteins that perform different functions. The proteins pack the DNA into chromosomes, ensuring its replication and its ability to read genetic information etc.
Anna Yudkina, an NSU graduate student and a co-author of the study explained,
Often, proteins can be" sewn " to our DNA. This can happen either spontaneously or, due to harmful external factors, such as radiation or salts from heavy metals that pollute the environment.
As a result, a protein sewn to DNA interferes with the cellular apparatus, which is responsible for replicating the DNA, and the cell could lose a piece of the genome or die preventing it from replicating its hereditary material.
In order for DNA to replicate itself within the cell, special proteins, known as DNA polymerases, will then respond. They move along the DNA chain, reproducing it. Under the supervision of Dmitry Zharkov, Doctor of Biological Sciences and Head of the Protein Engineering Laboratory, Novosibirsk scientists at the NSU SAU "Synthetic Biology", studied how a dozen DNA polymerases from different organisms collide when they are sewn to DNA proteins. It turned out that although sewn proteins present an insurmountable obstacle, some DNA polymerases are capable of pushing away molecules that interfere with them.
The results of their study provides a foundation for the development of new artificial DNA polymerases that will be able to "pass through" the DNA that is cross-linked to protein. These can be used later for many purposes including the genetic analysis of DNA from ancient bones or from conserved medical samples. In both of these cases, the cross-linking of proteins with DNA is a serious problem. This solution will increase the accuracy of the analysis and make it possible to use less material.