Scientists crack DNA's 'mechanical code'

DNA's mechanical code refers to the physical properties of DNA that are important
for its function as genetic material.
These properties include the double helix structure, the stability of base pairing, and the elasticity and flexibility
of molecules.
These properties allow DNA to store and transmit genetic information, and they are affected by various factors such as temperature, humidity, and pH
.

An international team of researchers, led by Durham University in the United Kingdom, has revealed a previously unknown way
in which nature encodes biological information in DNA sequences by deciphering the mechanical code of DNA.
The team used loop-seq, a next-generation DNA sequencing technology they developed, to demonstrate that specific base sequences along DNA fragments determine the local curvature
of molecules.

Through a large number of measurements, coupled with computational analysis and machine learning, they determined the mechanical code, the mapping
between the local sequence of DNA and the local deformation capacity.

In addition, the researchers found that the mechanical code of DNA can be modified by "methylation," a known chemical modification to which DNA bases are typically subjected at different stages of an organism's development
.
Methylation abnormalities have been linked
to several cancers.
The discovery that methylation alters the mechanical code suggests that biological development programs or diseases such as cancer may achieve their partial effects
on cells by altering the information encoded by the mechanical code.

The study was done by colleagues from Johns Hopkins University in the United States, the Barcelona Institute of Technology in Spain, and the University of Barcelona in Spain
.
The study has been published in the journal Nature Structural and Molecular Biology
.

Lead author Dr Aakash Basu of Durham University in the UK said: "DNA is a book
that contains the instructions a cell needs to survive.
But this is a very special kind of book, and your ability to turn the pages, repair cracks in the pages, or fold the pages depends on the words
written on the pages.
This is because in the Book of DNA, these words also somehow control the mechanical properties
of the paper.
”

They note that it is well known that reading, replicating, packing, and repairing genetic information stored in base sequences (As, Ts, Gs, and Cs) along DNA often involves processes
that require local mechanical deformation of DNA.

The evidence provided by the researchers suggests that in a variety of organisms, from mammals to bacteria, nature and evolution have utilized the mechanical code to locally control the deformability of DNA, which in turn controls key biological processes
that require mechanical deformation of DNA.

The researchers hope this knowledge will guide future developments in therapeutics and bioengineering
.

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