真核生物基因组(1).pptVIP免费

真核生物基因组分析一真核生物基因结构1启动子元件启动子(Promoter)在蛋白质编码基因中，启动子一般指基因5’端上游一段启动基因转录的核酸序列，是RNA聚合酶和转录因子结合的部位。而在rRNA和tRNA基因中，同时也包含了基因转录起始位点下游的一段序列。RNAPolIIisthefocusofeukaryotictranscription,becauseitisthemoststudiedpolymerase,andisalsoresponsiblefortranscribingmostgenes-indeed,essentiallyallprotein-encodinggenesRNAPolItranscribethelargeribosomalRNAprecursorgeneRNAPolIIItranscribetRNAgene,somesmallnuclearRNAgenesandthe5SrRNAgenesRNAPolIIformsapre-initiationcoRNAPolIIformsapre-initiationcomplexwithGTFsatthepromotermplexwithGTFsatthepromoterTheinvolvedGTFIIs(generaltranscriptionfactorforPolII)TFIID=TBP(TATAboxbindingprotein)+TAFs(TBPassociationfactors)TFIIA,B,F,E,HThetranscriptionineukaryotes51.TBPinTFIIDbindstotheTATAbox2.TFIIAandTFIIBarerecruitedwithTFIIBbindingtotheBRE3.RNAPolII-TFIIFcomplexisthenrecruited4.TFIIEandTFIIHthenbindupstreamofPolIItoformthepre-initiationcomplex5.PromotermeltingusingenergyfromATPhydrolysisbyTFIIHPromoterescapesafterthephosphorylationoftheCTDtail.PromoterescaperequiresphosphoPromoterescaperequiresphosphorylationoftheRNApolymeraseIIrylationoftheRNApolymeraseII“tail”“tail”StimulatedbyphosphorylationoftheCTD(C-terminaldomain)tailoftheRNAPolIICTDcontainstheheptapeptiderepeatTyr-Ser-Pro-Thr-Ser-Pro-SerPhosphorylationoftheCTD“tail”isconductedbyanumberofspecifickinasesincludingasubunitofTFIIHinvivoinvivo,transcriptioninitiationrequires,transcriptioninitiationrequiresadditionalproteinsadditionalproteinsRNAPolI&IIIrecognizedistinctpromotRNAPolI&IIIrecognizedistinctpromoters,usingdistinctsetsoftranscriptionfaers,usingdistinctsetsoftranscriptionfactors,butstillrequireTBP.ctors,butstillrequireTBP.PolI:transcribesrRNAprecursorencodinggene(multi-copygene)PolIII:transcribestRNAgenes,snRNAgenesand5SrRNAgenesRNAPolIpromoterrecognitionUpstreamcontrolelementUBFbindstotheupstreamofUCE,bringSL1tothedownstreampartofUCE.SL1inturnrecruitsRNAPolIto...