Taxonomic distribution of proteins containing CHROMO domains

The CHROMO domain within your query sequence starts at position 161 and ends at position 330, and its E-value is 1.08e-3.

A sequence motif found in a Drosophila heterochromatin protein is conserved in animals and plants.

Singh PB, Miller JR, Pearce J, Kothary R, Burton RD, Paro R, James TC, Gaunt SJ
Nucleic Acids Res. 1991; 19: 789-94

Modifiers of position-effect-variegation in Drosophila encode proteins that are thought to modify chromatin, rendering it heritably changed in its expressibility. In an attempt to identify similar modifier genes in other species we have utilized a known sequence homology, termed chromo box, between a suppressor of position-effect-variegation, Heterochromatin protein 1 (HP1), and a repressor of homeotic genes, Polycomb (Pc). A PCR generated probe encompassing the HP1 chromo box was used to clone full-length murine cDNAs that contain conserved chromo box motifs. Sequence comparisons, in situ hybridization experiments, and RNA Northern blot analysis suggest that the murine and human sequences presented in this report are homologues of the Drosophila HP1 gene. Chromo box sequences can also be detected in other animal species, and in plants, predicting a strongly conserved structural role for the peptide encoded by this sequence. We propose that epigenetic (yet heritable) changes in gene expressibility, characteristic of chromosomal imprinting phenomena, can largely be explained by the action of such modifier genes. The evolutionary conservation of the chromo box motif now enables the isolation and study of putative modifier genes in those animal and plant species where chromosomal imprinting has been described.

Imprinting a determined state into the chromatin of Drosophila.

Paro R
Trends Genet. 1990; 6: 416-21

The Polycomb gene of Drosophila melanogaster is a member of a class of genes involved in the clonal transmission of the repressed state of bomeotic regulatory genes through development. Genetic evidence, and the finding of a molecular similarity between the Polycomb protein and a heterochromatin-associated protein of Drosophila, suggest that this mechanism of repression might be imprinted in the structure of the chromatin, rather than being sustained through the action of diffusible regulatory factors.