Transcriptional control: The tight packing of DNA makes it less accessible for transcription that requires open access to the base sequence. Transcription factors (proteins) bind and interact with specific base sequences and achieve this more readily in histone-free DNA or in DNA that is more loosely packed. Thus the extent of DNA packaging in a cell regulates gene expression. In other words, one of the first steps in activating the transcription of a gene is to loosen the packaging by modifying the histones in specific ways, such as by methylation.
What are the roles of histones in the assembly of chromosomes?
Transcriptional control: The tight packing of DNA makes it less accessible for transcription that requires open access to the base sequence. Transcription factors (proteins) bind and interact with specific base sequences and achieve this more readily in histone-free DNA or in DNA that is more loosely packed. Thus the extent of DNA packaging in a cell regulates gene expression. In other words, one of the first steps in activating the transcription of a gene is to loosen the packaging by modifying the histones in specific ways, such as by methylation.
