/ H2A / Variant: H2A.B

Description

H2A.B, also known as "Barr body defficient" variant, it has been reported to be associated with transcription upregulation, splicing, DNA synthesis and spermiogenesis; it is also found in active genes at transcription start sites in testis. H2A.B is a rapildy evolving variant which is closely related to H2A.L and H2A.P. It is arginine rich, has a shortened C-terminal tail and docking domain and a smaller acidic patch. It is possible that mouse homolog of H2A.B, also called H2A.Lap1, bears modified function with respect to human H2A.B. H2A.Lap1 has additional negative residue in acidic patch, which is thought to increase its propensity to compact nucleosomal arrays relative to human H2A.B.
Alternate names: H2A.Bbd, H2A.Lap1(mouse)

Features

Below, you can explore the features of H2A.B from Homo sapiens, if available and how it compares to the canonical histones of the same type (first row). Canonical histone is shown in the first row, the names and descriptions of each feature can be found underneath. To explore variants from other species, please browse our curated sequences, automatically extracted sequences, or by taxonomy.

Keys: red - identical residues, blue - different residues (if more than one sequence).
Variant features
RRR
Stretch of arginines characteristic of H2A.B, at least in human
ap-
Loss of acidic patch residues
General histone type features
alpha1ext
Alpha1-extension helix
alpha1
Alpha1-helix, first helix of histone fold
loopL1
L1 loop, connecting first and second helices of histone fold. Part of L1L2 DNA binding site formed by H2A and H2B at SHL ±3.5.
beta1
Beta-strand in L1L2 DNA binding site
R1
Minor groove arginine at L1L2 DNA binding site, SHL ±3.5
alpha2
Alpha2-helix, second helix of histone fold
ap
Acidic patch residues
loopL2
L2 loop, connecting second and third helices of histone fold. Part of L1L2 DNA binding site formed by H2A and H2B at SHL ±5.5.
R2
Minor groove arginine at L1L2 DNA binding site, SHL ±5.5
beta2
Beta-strand in L1L2 DNA binding site
alpha3
Alpha3-helix, third helix of histone fold
Docking domain
Docking domain locking H2A-H2B dimer on H3-H4 tetramer surface
alpha3ext
Alpha3-extension helix
beta3
Beta-strand between H2A and H4

References

  1. Talbert PB, Ahmad K, et al. "A unified phylogeny-based nomenclature for histone variants." Epigenetics Chromatin, 2012. PMID: 22650316
  2. Shaytan AK, Landsman D, et al. "Nucleosome adaptability conferred by sequence and structural variations in histone H2A-H2B dimers." Curr Opin Struct Biol, 2015. PMID: 25731851
  3. Sugiyama M, Arimura Y, et al. "Distinct features of the histone core structure in nucleosomes containing the histone H2A.B variant." Biophys J, 2014. PMID: 24853749
  4. Gonzalez-Romero R, Mendez J, et al. "Quickly evolving histones, nucleosome stability and chromatin folding: all about histone H2A.Bbd." Gene, 2008. PMID: 18329190
  5. Eirin-Lopez JM, Ishibashi T, et al. "H2A.Bbd: a quickly evolving hypervariable mammalian histone that destabilizes nucleosomes in an acetylation-independent way." FASEB J, 2008. PMID: 17726088
  6. Nekrasov M, Soboleva TA, et al. "Histone variant selectivity at the transcription start site: H2A.Z or H2A.Lap1." Nucleus, 2013. PMID: 24213378
  7. Tolstorukov MY, Goldman JA, et al. "Histone variant H2A.Bbd is associated with active transcription and mRNA processing in human cells." Mol Cell, 2012. PMID: 22795134
  8. Sansoni V, Casas-Delucchi CS, et al. "The histone variant H2A.Bbd is enriched at sites of DNA synthesis." Nucleic Acids Res, 2014. PMID: 24753410
A set of manually selected and validated histone sequences is listed in the table. Click on an entry in the table to update the annotated sequence preview: a variant will be compared with the canonical histone from the same species (if available). Alternatively, tick mark the sequences and use toolbar to view MSA, export or add to basket. Use search or filters to find particular entries.
Keys: red - identical residues, blue - different residues (if more than one sequence). For feature legend see summary tab.
Sequence preview and annotation... LOADING





Min Score
Max Score
102.7
203.5

You selected: root

Note: variant classification might be ambigous between very similar variants. Classification scores against all variant models are available via advanced menu.
Features characteristic for a given histone type/variant are marked below the consensus sequence. For feature description see summary tabs of the corresponding variants pages.
Keys: red - 80% identical, blue - 50% identical columns. X-ambigous positions in consensus sequence.