How DNA Is Unwound So That Its Code Can Be Read
DNA can be found in every living organism. “[It is] the material inside the nucleus of cells that carries genetic information” (Your Genes, Your Choices: Glossary). The genetic information is consisted of two strands twisted together and is encoded in the sequence of nucleotides, which are deoxyribose, phosphate group, and nitrogen bases. This genetic information is also heritable traits which can be carried onto future offsprings. In an article read named “Scripps Research scientists shed light on how DNA is unwound so that its code can be read,” “researchers… have figured out how a molecular machine is able to unwind the DNA.” “The structure [they] have solved provides important clues into one of the first steps in gene expression regulation,” says Francisco Asturias, the study’s lead investigator.
Beyond of the fact that this macromolecular machine unwinds DNA, it records images of “individual molecules persevered at extremely low temperatures” (Scripps Research). The researchers tested out samples from yeast Saccharomyces cerevisiae and then used mathematics and intensive digital processing to translate the images of single RSC molecules. RSC is a large and flexible machine of thirteen different proteins that unwinds the DNA. Given the fact that we have trillions of cells within our body, it is said that when the DNA is stretched out it would be too long to even be counted. This is the reason why DNA is built into little chromosomes. Researchers are set out to understand the complexity of unwinding “DNA from the many histone beads within a gene so that other molecular machines can read the genetic codes” (Scripps Research). “By using energy from an external source (ATP hydrolysis) RSC can repeatedly pull DNA away from the histones and eventually expose [the entire] DNA,” says Asturias. However, the nucleosome to which the RSC is bounded is still intact, even though, the DNA is exposed. Austria also...
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