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 H4
Features
Below, you can explore the features of canonical H4 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
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 H3 and H4 at SHL ±2.5.
beta1
Beta-strand in L1L2 DNA binding site
R2
Minor groove arginine at L1L2 DNA binding site, SHL ±0.5
alpha2
Alpha2-helix, second helix of histone fold
loopL2
L2 loop connecting second and third helices of histone fold. Part of L1L2 DNA binding site formed by H3 and H4 at SHL ±0.5.
beta2
Beta-strand in L1L2 DNA binding site
alpha3
Alpha3-helix, third helix of histone fold
beta3
Beta-strand between H4 and H2A docking domain
References
Talbert PB, Ahmad K, et al. "A unified phylogeny-based nomenclature for histone variants." Epigenetics Chromatin, 2012. PMID: 22650316
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.