As chromatin is condensed into the primary nucleosome structure, DNA becomes less accessible for transcription factors. With the loosening of this chromatin structure, however, transcription machinery is better able to access the genomic DNA, and transcription is thus promoted.
Is chromatin structure altered during transcription?
Transcription or replication may alter chromatin structure during synthesis, enabling regulatory factor binding and, potentially, future rounds of transcription.
Does chromatin reduce transcription?
Thus the extent of compaction of the chromatin in the different states will affect the ability of transcription factors, polymerases, repair enzymes, and the recombination machinery to access this substrate. More open, accessible chromatin is associated with greater transcriptional activity.
What is the difference between DNA and chromatin?
The DNA is packaged by special proteins called histones to form chromatin. The chromatin further condenses to form chromosomes.
|Difference between Chromosomes and Chromatin|
|Composed of nucleosomes||They are condensed chromatin fibers|
What happens to histones during transcription?
At the same time, during intense transcription histones are largely removed from DNA in vivo. Under these circumstances, histone-free DNA could be available for binding to the transiently exposed octamer surface, and translocation of the nucleosomes remaining on the genes would become much more likely.
What are the two types of chromatin?
Chromatin exists in two forms. One form, called euchromatin, is less condensed and can be transcribed. The second form, called heterochromatin, is highly condensed and is typically not transcribed.
How many chromatin do cells have?
So there is one chromatin per one chromosome. This tight packing is important in making sure this long string of DNA can fit inside the cell’s nucleus.