Chromo Domain

Domain Binding and Function

The Chromatin Organization Modifier (Chromo) domain is defined as a 30–70 amino acid residue protein module found in a number of proteins involved in the assembly of protein complexes on chromatin. This domain was first described in Drosophila modifiers of variegation, which are proteins that modify the structure of chromatin to the condensed morphology of heterochromatin, a cytologically visible condition where gene expression is repressed. Examples of chromo-domain-containing proteins include the HP1 molecule involved in repression of gene expression in heterochromatin, the Polycomb (Pc) transcriptional repressors of homeotic genes in which the chromodomain is essential for chromatin targeting, and human retinoblastoma binding protein (RBP-1). Some chromo domain (CD) proteins contain an N-terminal chromo domain and a C-terminal Shadow Chromo Domain (CSD).

Structure Reference

1. Ball, L.J. et al. (1997) EMBO J. 16(9), 2473–2481.

Examples of Domain Proteins

Binding Examples

Chromodomain Protein	Binding Partners
HP1	Histone H3 methylated lysine-9