Tag : Manipulate

Washington: A human cell contains around 2 metres of DNA, which contains an individual's important genetic information. If all the DNA contained within a single person were unwound and stretched out, it would cover an astonishing distance - enough to reach the sun and back 60 times over. The cell compacts its DNA into densely packed chromosomes in order to manage such a massive amount of biological information. "Imagine DNA as a piece of paper upon which all our genetic information is written." Said Minke A.D. Nijenhuis, co-corresponding author. "The paper is folded into a very tight structure in order to fit all of that information into a small cell nucleus. To read the information, however, parts of the paper have to be unfolded and then refolded. This spatial organization of our genetic code is a central mechanism of life. We therefore wanted to create a methodology that allows researchers to engineer and study the compaction of double-stranded DNA." Natural DNA is frequently double-stranded, with one strand encoding the genes and one strand acting as a backup, interwoven in a double helix. Watson-Crick interactions, which allow the two strands to recognise and pair with one another, stabilise the double helix. However, there is another, lesser-known class of DNA interactions. These contacts, known as normal or reverse Hoogsteen interactions, allow a third strand to join in, resulting in a stunning triple helix. In a recent paper, published in Advanced Materials, researchers from the Gothelf lab debut a general method to organize double-stranded DNA, based on Hoogsteen interactions. The study unambiguously demonstrates that triplex-forming strands are capable of sharply bending or "folding" double-stranded DNA to create compacted st ...