UniProtSummary | FUNCTION:Corecomponentofnucleosome.NucleosomeswrapandcompactDNAintochromatin,limitingDNAaccessibilitytothecellularmachinerieswhichrequireDNAasatemplate.Histonestherebyplayacentralroleintranscriptionregulation,DNArepair,DNAreplicationandchromosomalstability.DNAaccessibilityisregulatedviaacomplexsetofpost-translationalmodificationsofhistones,alsocalledhistonecode,andnucleosomeremodeling. Hasbroadantibacterialactivity.Maycontributetotheformationofthefunctionalantimicrobialbarrierofthecolonicepithelium,andtothebactericidalactivityofamnioticfluid. SUBUNITSTRUCTURE:ThenucleosomeisahistoneoctamercontainingtwomoleculeseachofH2A,H2B,H3andH4assembledinoneH3-H4heterotetramerandtwoH2A-H2Bheterodimers.Theoctamerwrapsapproximately147bpofDNA. SUBCELLULARLOCATION:Nucleus.Chromosome. PTM:MonoubiquitinationofLys-121bytheRNF20/40complexgivesaspecifictagforepigenetictranscriptionalactivationandisalsoprerequisiteforhistoneH3"Lys-4"and"Lys-79"methylation.ItalsofunctionscooperativelywiththeFACTdimertostimulateelongationbyRNApolymeraseII. PhosphorylatedonSer-15bySTK4/MST1duringapoptosis;whichfacilitatesapoptoticchromatincondensation.AlsophosphorylatedonSer-15inresponsetoDNAdoublestrandbreaks(DSBs),andincorrelationwithsomatichypermutationandimmunoglobulinclass-switchrecombination. SEQUENCESIMILARITIES:BelongstothehistoneH2Bfamily. |