4v2v
From Proteopedia
JMJD2A COMPLEXED WITH NI(II), NOG AND HISTONE H3K27me3 PEPTIDE (25-29) ARK(me3)SA
Structural highlights
Function[KDM4A_HUMAN] Histone demethylase that specifically demethylates 'Lys-9' and 'Lys-36' residues of histone H3, thereby playing a central role in histone code. Does not demethylate histone H3 'Lys-4', H3 'Lys-27' nor H4 'Lys-20'. Demethylates trimethylated H3 'Lys-9' and H3 'Lys-36' residue, while it has no activity on mono- and dimethylated residues. Demethylation of Lys residue generates formaldehyde and succinate. Participates in transcriptional repression of ASCL2 and E2F-responsive promoters via the recruitment of histone deacetylases and NCOR1, respectively.[1] [2] [3] Isoform 2: Crucial for muscle differentiation, promotes transcriptional activation of the Myog gene by directing the removal of repressive chromatin marks at its promoter. Lacks the N-terminal demethylase domain.[4] [5] [6] [H31T_HUMAN] Core component of nucleosome. Nucleosomes wrap and compact DNA into chromatin, limiting DNA accessibility to the cellular machineries which require DNA as a template. Histones thereby play a central role in transcription regulation, DNA repair, DNA replication and chromosomal stability. DNA accessibility is regulated via a complex set of post-translational modifications of histones, also called histone code, and nucleosome remodeling. Publication Abstract from PubMedThe JmjC-domain-containing 2-oxoglutarate-dependent oxygenases catalyze protein hydroxylation and N()-methyllysine demethylation via hydroxylation. A subgroup of this family, the JmjC lysine demethylases (JmjC KDMs) are involved in histone modifications at multiple sites. There are conflicting reports as to the substrate selectivity of some JmjC oxygenases with respect to KDM activities. In this study, a panel of modified histone H3 peptides was tested for demethylation against 15 human JmjC-domain-containing proteins. The results largely confirmed known N()-methyllysine substrates. However, the purified KDM4 catalytic domains showed greater substrate promiscuity than previously reported (i.e., KDM4A was observed to catalyze demethylation at H3K27 as well as H3K9/K36). Crystallographic analyses revealed that the N()-methyllysine of an H3K27me3 peptide binds similarly to N()-methyllysines of H3K9me3/H3K36me3 with KDM4A. A subgroup of JmjC proteins known to catalyze hydroxylation did not display demethylation activity. Overall, the results reveal that the catalytic domains of the KDM4 enzymes may be less selective than previously identified. They also draw a distinction between the N()-methyllysine demethylation and hydroxylation activities within the JmjC subfamily. These results will be of use to those working on functional studies of the JmjC enzymes. Studies on the catalytic domains of multiple JmjC oxygenases using peptide substrates.,Williams ST, Walport LJ, Hopkinson RJ, Madden SK, Chowdhury R, Schofield CJ, Kawamura A Epigenetics. 2014 Dec 2;9(12):1596-603. doi: 10.4161/15592294.2014.983381. PMID:25625844[7] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. References
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Categories: Chowdhury, R | Madden, S K | Schofield, C J | 2-oxoglutarate | Chromatin regulator | Dioxygenase | Double-stranded beta helix | Dsbh | Epigenetic and transcription regulation | Facial triad | Hydroxylation | Iron | Jmjc domain | Metal binding protein | Non-heme | Oxidoreductase | Oxygenase
