Sandbox GGC1

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You may include any references to papers as in: the use of JSmol in Proteopedia ^[1] or to the article describing Jmol ^[2] to the rescue.

Function

The Variant histone H3 replaces H3 in a range of nucleosomes in active genes. Deposited at sites of nucleosomal displacement throughout transcribed genes, suggesting that it represents an epigenetic imprint of transcriptionally active chromatin. 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

Disease

There are mutations in H3.3 that are found in different types of bone tumors like chrondroblastoma for example and giant cell tumors of the bone Chondroblastoma arises in children and in young adults in the cartilage of the growth plates of the long bones and is most typically benign.

Relevance

Histone octamer containing two of H2A, H2B, H3 and H4 and the octamer wraps 147bp of DNA. H3.3 interacts with HIRA which is a chaperone and ZMYND11 when trimethylated at Lysine-36

Structural highlights

in a PubMed abstract,CENP-Awhich is a centromere-specific histone H3 variant is over expressed in cancer cells and it can be mislocalized ectopically in the form of heterotypic nucleosomes containing H3.3.