This article has been reviewed according to Science X's editorial process and policies. Editors have highlighted the following attributes while ensuring the content's credibility: Nearly every cell in the human body contains essentially the same genetic information, yet different cells activate different genes. For regulatory proteins to reach these genes, DNA must be accessible.
This accessibility depends not only on the genetic code itself but also on DNA's physical properties—its shape, flexibility and ability to interact with proteins. Researchers are exploring what is known as DNA's physical code—the molecule's physical properties, which may influence how cells use the genetic information encoded within DNA. An international team of researchers, including Dr.
Daiva Petkevičiūtė-Gerlach from Kaunas University of Technology (KTU), investigated this code on an unprecedented scale by performing atomistic simulations and analyses of the shape, flexibility and dynamics of a large set of DNA sequences. The paper is published in the journal Nature Communications. "Most of us know that DNA is a long, thin molecule in which the genetic information of all living organisms is encoded in a sequence of four nucleotides—adenine (A), thymine (T), guanine (G) and cytosine (C)," says Petkevičiūtė-Gerlach, a researcher at KTU's Faculty of Mathematics and Natural Sciences.
She explains that the sequence of nucleotides determines not only the information stored in DNA but also the molecule's shape, flexibility and ability to move. As a result, two different DNA segments may differ not only in the genetic information they contain but also in the way they bend, deform or interact with other molecules within the cell. "The physical properties of DNA, which depend on its nucleotide sequence, influence how it interacts with proteins and therefore play an important role in gene expression.
For example, proteins that regulate gene activity recognize not only the specific nucleotide sequence when binding to DNA but also its three-dimensional structure, shape and flexibility," Petkevičiūtė-Gerlach explains. This is particularly important because DNA is not freely extended within the cell. To fit the long molecule into the small cell nucleus, DNA wraps around histone protein complexes to form nucleosomes.
This arrangement allows the genetic material to be packed compactly, but at the same time, it can restrict access to certain regions of the DNA. If a particular DNA region bends or rearranges more easily, it may be more accessible to cellular proteins. Conversely, stiffer or more tightly packed regions may remain harder to access.
Extract — continue reading at the source.
