Canonical histones are replication-dependent while histone variants are replication-independent, constitutively expressed during cell cycle. Genes encoding canonical histones are typically located within multigene clusters and use specific type of regulation at the RNA level with a stem loop structure instead of polyA tail Alternate names: ca H2B
Features
Below, you can explore the features of canonical H2B from Homo sapiens, if available. 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).
General histone type features
R1
Minor groove arginine at alpha1-alpha1 DNA binding site at SHL ±4.5.
alpha1
Alpha1-helix, first helix of histone fold
loopL1
L1 loop, connecting first and second helices of histone fold. Part of the L1L2 DNA binding site formed by H2A and H2B at SHL ±5.5.
beta1
Beta-strand in the L1L2 DNA binding site
alpha2
Alpha2-helix, second helix of histone fold
loopL2
L2 loop, connecting second and third helices of the histone fold. Part of the L1L2 DNA binding site formed by H2A and H2B at SHL ±3.5.
beta2
Beta-strand in the L1L2 DNA binding site
alpha3
Alpha3-helix, third helix of the histone fold
alphaC
AlphaC-helix
References
Talbert PB, Ahmad K, et al. "A unified phylogeny-based nomenclature for histone variants." Epigenetics Chromatin, 2012. PMID: 22650316
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
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
Keys: red - 80% identical, blue - 50% identical columns. X-ambigous positions in consensus sequence. For feature legends see summary tabs of the corresponding variant pages.
Sequence(s)
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.
Note: variant classification might be ambigous between very similar variants. Classification scores against all variant models are available via advanced menu.
Keys: red - 80% identical, blue - 50% identical columns. X-ambigous positions in consensus sequence. For feature legends see summary tabs of the corresponding variant pages.
Sequence(s)
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.
All Profile Scores
Score shows how well a sequence was classified by a variant HMM. Each sequence has been classified as a variant (Green), but it may share similar functions to another variant (Blue). Please see the 'Help' page to learn about the classification algorithm. Score thresholds used to classify the variants are listed in parentheses.
Key:
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.