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Interactions Between HP1 Chromodomain and H3 Trimethyllysine9 Histone Tail
Author(s) -
Eisert Robyn J,
Waters Marcey
Publication year - 2011
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.25.1_supplement.896.4
Subject(s) - chromodomain , heterochromatin protein 1 , histone , histone h3 , genetics , biology , chemistry , gene , biochemistry , microbiology and biotechnology , computational biology , heterochromatin , chromatin , helicase , rna
Recent findings suggest that a variety of post‐translational modifications (PTMs) on N‐terminal tails of histones are intricately involved in DNA packaging and directly control levels of gene expression. One such modification is the methylation of lysine9 on the H3 histone tail, which recruits heterochromatin protein 1 (HP1) via its chromodomain and results in silenced gene expression. The HP1 chromodomain binds the H3 K9Me 3 with a K D of 17 μM with an aromatic cage surrounding the trimethyllysine. The histone tail is also inserted between two β‐strands of the chromodomain to form a 3‐stranded β‐sheet. Here, we are studying the sequence selectivity provided by the β‐sheet interactions and how those interactions compare to other model systems. Residue Thr6 of the histone tail forms cross‐strand interactions with Ala25 and Asp 62 of the chromodomain. Each of these three residues was systematically substituted for amino acids known to form favorable interactions in β‐sheets including hydrophobic, hydrogen‐bonding, and aromatic interactions. These studies were able to provide insights into the sequence selectivity of the chromodomain for the histone tail and demonstrated the applicability of information gleaned from model systems and statistical studies to protein‐protein recognition.