DNAsilmukoitumus

DNAsilmukoitumus, also known as DNA coiling or DNA supercoiling, refers to the process where the DNA double helix twists upon itself. This twisting is a fundamental aspect of DNA organization within cells, especially in prokaryotes and eukaryotes.

The DNA molecule is a double helix, and this helix can be further twisted or coiled. This coiling can occur in two directions: positive supercoiling, where the DNA is overwound, and negative supercoiling, where it is underwound. The degree of supercoiling is quantified by the linking number, which reflects the number of times one DNA strand winds around the other.

Supercoiling plays a crucial role in DNA packaging, allowing the long DNA molecule to fit within the confined space of a cell nucleus or nucleoid. It also influences DNA replication, transcription, and repair by altering the local structure of the DNA, making it more or less accessible to enzymes. Enzymes called topoisomerases are responsible for managing and regulating the level of supercoiling in DNA. They can introduce or remove supercoils by breaking and rejoining the DNA strands.

While essential for cellular function, excessive or improperly regulated supercoiling can be detrimental. The maintenance of a balanced superhelical state is therefore tightly controlled by cellular machinery. Understanding DNAsilmukoitumus is vital for comprehending DNA topology and its impact on genetic processes.