简介:Transcriptionfactor(TF)bindingtoitsDNAtargetsiteplaysanessentialroleingeneregulation.Thelocation,orientationandspacingoftranscriptionfactorbindingsites(TFBSs)alsoaffectregulatoryfunctionoftheTF.However,hownucleosomalcontextofTFBSsinfluencesTFbindingandsubsequentgeneregulationremainstobeelucidated.Usinggenome-widenucleosomepositioningandTFbindingdatainbuddingyeast,wefoundthatbindingaffinitiesofTFstoDNAtendtodecreasewithincreasingnucleosomeoccupancyoftheassociatedbindingsites.WefurtherdemonstratedthatnucleosomalcontextofbindingsitesiscorrelatedwithgeneregulationofthecorrespondingTF.Nucleosome-depletedTFBSsarelinkedtohighgeneactivityandlowexpressionnoise,whereasnucleosome-coveredTFBSsareassociatedwithlowgeneactivityandhighexpressionnoise.Moreover,nucleosome-coveredTFBSstendtodisruptcoexpressionofthecorrespondingTFtargetgenes.WeconcludethatnucleosomalcontextofbindingsitesinfluencesTFbindingaffinity,subsequentlyaffectingtheregulationofTFsontheirtargetgenes.ThisemphasizestheneedtoincludenucleosomalcontextofTFBSsinmodelinggeneregulation.