UniProt functional annotation for P06897

UniProt code: P06897.

Organism: Xenopus laevis (African clawed frog).
Taxonomy: Eukaryota; Metazoa; Chordata; Craniata; Vertebrata; Euteleostomi; Amphibia; Batrachia; Anura; Pipoidea; Pipidae; Xenopodinae; Xenopus; Xenopus.
 
Function: 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.
 
Subunit: The nucleosome is a histone octamer containing two molecules each of H2A, H2B, H3 and H4 assembled in one H3-H4 heterotetramer and two H2A-H2B heterodimers. The octamer wraps approximately 147 bp of DNA.
Subcellular location: Nucleus. Chromosome.
Ptm: Monoubiquitination of Lys-120 (H2AK119Ub) gives a specific tag for epigenetic transcriptional repression. Following DNA double-strand breaks (DSBs), it is ubiquitinated through 'Lys-63' linkage of ubiquitin moieties, leading to the recruitment of repair proteins to sites of DNA damage. H2AK119Ub and ionizing radiation-induced 'Lys-63'- linked ubiquitination are distinct events (By similarity). {ECO:0000250}.
Ptm: Phosphorylation on Ser-2 is enhanced during mitosis. Phosphorylation on Ser-2 directly represses transcription (By similarity). {ECO:0000250}.
Ptm: Glutamine methylation at Gln-105 (H2AQ104me) by FBL is specifically dedicated to polymerase I. It is present at 35S ribosomal DNA locus and impairs binding of the FACT complex (By similarity). {ECO:0000250}.
Similarity: Belongs to the histone H2A family. {ECO:0000305}.

Annotations taken from UniProtKB at the EBI.