One possible reason is that elongation factors may maintain an open chromatin structure of highly transcribed snRNA genes.
Chromatin analysis reveals that H3mm7 facilitates transcription by forming an open chromatin structure around promoter regions including those of myogenic genes.
This open chromatin structure is termed "euchromatin".
Such elevated CpG density may protect the regions from methylation and allows an open chromatin structure to increase binding probability of ubiquitous transcription factors (Deaton and Bird 2011).
This indicates that region-specific characteristics, such as an open chromatin structure, might facilitate replication initiation.
Cells transfected with scrambled SiRNA demonstrated a more open chromatin structure over this 200 bp region.
In this system, NF-Y target genes are actively transcribed, and their promoters have an open chromatin structure.
Barrier elements are required to maintain nucleosome organization and histone modifications associated with an open chromatin structure [30].
These observations have led to the idea that an open chromatin structure may be required for stem cell pluripotency.
Essential genes for example cluster in regions with open chromatin structure to reduce noise in expression patterns [4].
The activity of MSL is thought to facilitate hyper-transcription by leading to more open chromatin structure.
