In molecular biology, the chromo shadow domain is a
protein domain which is distantly related to the
chromodomain. It is always found in association with a chromodomain.
Proteins containing a chromo shadow domain include ''
Drosophila'' and
human heterochromatin
Heterochromatin is a tightly packed form of DNA or '' condensed DNA'', which comes in multiple varieties. These varieties lie on a continue between the two extremes of constitutive heterochromatin and facultative heterochromatin. Both play a role ...
protein Su(var)205 (HP1); and
mammalian modifier 1 and modifier 2.
Chromo shadow domains self-aggregate, bringing together the
nucleosomes to which their proteins are bound and thus condense the
chromatin region they are associated with. Condensed chromatin is not able to be
transcribed as the transcription factors and enzymes are not able to access to DNA sequence in this form. Hence chromoshadow domain containing proteins repress gene transcription.
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References
External links
* {{ELM, LIG_HP1_1
Protein domains