UniProtSummary | FUNCTION:SwissProt:Q8N257#Corecomponentofnucleosome.NucleosomeswrapandcompactDNAintochromatin,limitingDNAaccessibilitytothecellularmachinerieswhichrequireDNAasatemplate.Histonestherebyplayacentralroleintranscriptionregulation,DNArepair,DNAreplicationandchromosomalstABIlity.DNAaccessibilityisregulatedviaacomplexsetofpost-translationalmodificationsofhistones,alsocalledhistonecode,andnucleosomeremodeling. SIZE:126aminoacids;13908Da SUBUNIT:ThenucleosomeisahistoneoctamercontainingtwomoleculeseachofH2A,H2B,H3andH4assembledinoneH3-H4heterotetramerandtwoH2A-H2Bheterodimers.Theoctamerwrapsapproximately147bpofDNA. SUBCELLULARLOCATION:Nucleus. PTM:MonoubiquitinationofLys-121bytheRNF20/40complexgivesaspecifictagforepigenetictranscriptionalactivationandisalsoprerequisiteforhistoneH3"Lys-4"and"Lys-79"methylation.ItalsofunctionscooperativelywiththeFACTdimertostimulateelongationbyRNApolymeraseII.&PhosphorylatedonSer-15bySTK4/MST1duringapoptosis;whichfacilitatesapoptoticchromatincondensation.AlsophosphorylatedonSer-15inresponsetoDNAdoublestrandbreaks(DSBs),andincorrelationwithsomatichypermutationandimmunoglobulinclass-switchrecombination. SIMILARITY:SwissProt:Q8N257##BelongstothehistoneH2Bfamily. |