1、1Dr.Fu Qiang. Dept.of Biochemistry & Molecular Biology, Preclinical Medicine School, SCU, 2006. 11Replication: Biosynthesis of DNA PART III. FLOW OF GENETIC INFORMATION 2Dr.Fu Qiang. Dept.of Biochemistry & Molecular Biology, Preclinical Medicine School, SCU, 2006. 11Replication: Biosynthesis of DNA基

2、因信息的傳遞PART III. FLOW OF GENETIC INFORMATION3Dr.Fu Qiang. Dept.of Biochemistry & Molecular Biology, Preclinical Medicine School, SCU, 2006. 11Replication: Biosynthesis of DNA PART III. FLOW OF GENETIC INFORMATION 1. This part concerns the biochemical mechanismscontradictoryunderlyingtheapparentlyrequ

3、irements for both genetic continuity and theevolution of living organisms. 14Dr.Fu Qiang. Dept.of Biochemistry & Molecular Biology, Preclinical Medicine School, SCU, 2006. 11Replication: Biosynthesis of DNA PART III. FLOW OF GENETIC INFORMATION 1. This part concerns the biochemical mechanismsunderly

4、ingtheapparentlycontradictoryrequirements for both genetic continuity and the evolution of living organisms. 12.Thefundamentalunitofinformationinlivingsystems is the gene.5Dr.Fu Qiang. Dept.of Biochemistry & Molecular Biology, Preclinical Medicine School, SCU, 2006. 11Replication: Biosynthesis of DN

5、A PART III. FLOW OF GENETIC INFORMATION 1. This part concerns the biochemical mechanismsunderlyingtheapparentlycontradictoryrequirements for both genetic continuity and the evolution of living organisms. 1編碼2.Thefundamentalunitofinformation inlivingsystems is the gene.A gene can be defined biochemic

6、ally as a segment of DNA (or, in a few cases, RNA) that encodes the5informationrequiredtoproduceafunctionalbiological product.6Dr.Fu Qiang. Dept.of Biochemistry & Molecular Biology, Preclinical Medicine School, SCU, 2006. 11Replication: Biosynthesis of DNAThecentral prisesthethreemajorproc

7、essesinthecellularutilizationofgenetic information. 2中心法則7Dr.Fu Qiang. Dept.of Biochemistry & Molecular Biology, Preclinical Medicine School, SCU, 2006. 11Replication: Biosynthesis of DNACENTRAL DOGMA:Thecentraldogmaof molecularbiologyistheoriginal proposalthatDNAmakesRNAmakesprotein,showingthegener

8、alpathwaysofinformation flow via replication, transcription, andtranslation8Dr.Fu Qiang. Dept.of Biochemistry & Molecular Biology, Preclinical Medicine School, SCU, 2006. 11Replication: Biosynthesis of DNA3.Thecentraldogmacomprisesthethreemajorprocessesinthecellularutilizationofgenetic information.

9、2The first is replication, the copying of parental DNA5to form daughter DNA molecules with identicalnucleotide sequences.9Dr.Fu Qiang. Dept.of Biochemistry & Molecular Biology, Preclinical Medicine School, SCU, 2006. 11Replication: Biosynthesis of DNA3.Thecentraldogmacomprisesthethreemajorprocessesi

10、nthecellularutilizationofgenetic information. 2The first is replication, the copying of parental DNA to fo m daughter DNA molecules with identical5nuclede sequences.Theond is transcription, the process by which5parts of the genetic message encoded in DNA arecopied precisely into RNA.10Dr.Fu Qiang. D

11、ept.of Biochemistry & Molecular Biology, Preclinical Medicine School, SCU, 2006. 11Replication: Biosynthesis of DNA3.Thecentraldogmacomprisesthethreemajorprocessesinthecellularutilizationofgenetic information. 2The first is replication, the copying of parental DNA to form daughter DNA molecules with

12、 identical nucleotide sequences.The second is transcription, the process by which parts of the genetic message encoded in DNA are copied precisely into RNA.55Thethirdistranslation,wherebythegenetic5message encoded in messenger RNA is translatedontheribosomesintoapolypeptidewithaparticular sequence o

13、f amino acids.11Dr.Fu Qiang. Dept.of Biochemistry & Molecular Biology, Preclinical Medicine School, SCU, 2006. 11Replication: Biosynthesis of DNA The central dogma of molecular biology. Itshowsthegeneral pathways of information flow via replication, transcription, and translation. Theterm “dogma” is

14、 a misnomer. Introduced by Francis Crick at a time when little evidence supported these ideas, the dogma has become a well-established principle.12Dr.Fu Qiang. Dept.of Biochemistry & Molecular Biology, Preclinical Medicine School, SCU, 2006. 11Replication: Biosynthesis of DNA13Dr.Fu Qiang. Dept.of B

15、iochemistry & Molecular Biology, Preclinical Medicine School, SCU, 2006. 11Replication: Biosynthesis of DNANOTE:The central dogma is broadly correct, although anumber of examples are known which contradictparts ofit.RetrovirusesreversetranscribeRNAintoDNA,anumberofvirusesareabletoreplicate Rdirectly

16、 into an RNA copy, and anumberof o ganisms can edit a messenger RNAsequencenot diresothattheproteincodingsequenceisspecified by DNA sequence.14Dr.Fu Qiang. Dept.of Biochemistry & Molecular Biology, Preclinical Medicine School, SCU, 2006. 11Replication: Biosynthesis of DNA逆轉(zhuǎn)錄酶versetranscriptasesTheex

17、istenceofinRNAviruses was predicby Howard Temin in 1962,wereultimatelydetectedbyandtheenzymesTemin and, independently, by David Baltimore in1970. Their discovery aroused much attention as dogma-shaking proof that genetic information can flow “backward” from RNA to DNA.15Dr.Fu Qiang. Dept.of Biochemi

18、stry & Molecular Biology, Preclinical Medicine School, SCU, 2006. 11Replication: Biosynthesis of DNATheexistenceofersetranscriptasesinRNAviruses was predictby Howard Temin in 1962,andtheenzymeswereultimatelydetectedby Temin and, independently, by David Baltimore in1970. Their discovery aroused much

19、attention asdogma-shaking proof that genetic information canflow “backward” from RNA to DNA.16Dr.Fu Qiang. Dept.of Biochemistry & Molecular Biology, Preclinical Medicine School, SCU, 2006. 11Replication: Biosynthesis of DNA Extension of the central dogma to include RNA-dependent synthesis of RNA and

20、 DNA.17Dr.Fu Qiang. Dept.of Biochemistry & Molecular Biology, Preclinical Medicine School, SCU, 2006. 11Replication: Biosynthesis of DNAIntroductionFundamental RulesMajor enzymesProcessReverse TranscriptionDNA Damage and RepairSummaryProblemsChapter 10. Biosynthesis of DNAReplication18Dr.Fu Qiang. D

21、ept.of Biochemistry & Molecular Biology, Preclinical Medicine School, SCU, 2006. 11Replication: Biosynthesis of DNADNA的生物合成復(fù)制IntroductionFundamental RulesMajor enzymesProcessReverse TranscriptionDNA Damage and RepairSummaryProblemsChapter 10. Biosynthesis of DNAReplication19Dr.Fu Qiang. Dept.of Bioc

22、hemistry & Molecular Biology, Preclinical Medicine School, SCU, 2006. 11Replication: Biosynthesis of DNAContents:10.0 Introduction10.4Fundamental Rules of ReplicationEnzymology and Topology of Replication Process of ReplicationReverse Transcription10.5DNA Damage and RepairSummary Problem

23、sIntroductionFundamental RulesMajor enzymesProcessReverse TranscriptionDNA Damage and RepairSummaryProblemsChapter 10. Biosynthesis of DNAReplication20Dr.Fu Qiang. Dept.of Biochemistry & Molecular Biology, Preclinical Medicine School, SCU, 2006. 11Replication: Biosynthesis of DNABrief introduction:I

24、ntroductionFundamental RulesMajor enzymesProcessReverse TranscriptionDNA Damage and RepairSummaryProblems21Dr.Fu Qiang. Dept.of Biochemistry & Molecular Biology, Preclinical Medicine School, SCU, 2006. 11Replication: Biosynthesis of DNABrief introduction:5TheprimaryfunctionofDNAreplicationisundersto

25、od to be the provision of progeny with the genetic information possessed by the parent. 3IntroductionFundamental RulesMajor enzymesProcessReverse TranscriptionDNA Damage and RepairSummaryProblems22Dr.Fu Qiang. Dept.of Biochemistry & Molecular Biology, Preclinical Medicine School, SCU, 2006. 11Replic

26、ation: Biosynthesis of DNABrief introduction:5TheprimaryfunctionofDNAreplicationisunderstood to be the provision of progeny with thegenetic information possessed by the parent. 3Replication is semiconservative, each strand acting5as template for a new daughter strand.半保留的IntroductionFundamental Rule

27、sMajor enzymesProcessReverse TranscriptionDNA Damage and RepairSummaryProblems23Dr.Fu Qiang. Dept.of Biochemistry & Molecular Biology, Preclinical Medicine School, SCU, 2006. 11Replication: Biosynthesis of DNABrief introduction:5TheprimaryfunctionofDNAreplicationisunderstood to be the provision of p

28、rogeny with thegenetic information possessed by the parent. 3Replication is semiconservative, each strand acting as template for a new daughter strand. It is carried5outinthreeidentifiablephases:initiation,elongation, and termination.起始IntroductionFundamental RulesMajor enzymesProcessReverse Transcr

29、iptionDNA Damage and RepairSummaryProblems24Dr.Fu Qiang. Dept.of Biochemistry & Molecular Biology, Preclinical Medicine School, SCU, 2006. 11Replication: Biosynthesis of DNABrief introduction:5TheprimaryfunctionofDNAreplicationisunderstood to be the provision of progeny with thegenetic information p

30、ossessed by the parent. 3Replication is semiconservative, each strand acting as template for a new daughter strand. It is carried5outinthreeidentifiablephases:initiation,elongation, and termination.延長(zhǎng)IntroductionFundamental RulesMajor enzymesProcessReverse TranscriptionDNA Damage and RepairSummaryPr

31、oblems25Dr.Fu Qiang. Dept.of Biochemistry & Molecular Biology, Preclinical Medicine School, SCU, 2006. 11Replication: Biosynthesis of DNABrief introduction:5TheprimaryfunctionofDNAreplicationisunderstood to be the provision of progeny with thegenetic information possessed by the parent. 3Replication

32、 is semiconservative, each strand acting as template for a new daughter strand. It is carried5outinthreeidentifiablephases:initiation,elongation, and termination.終止IntroductionFundamental RulesMajor enzymesProcessReverse TranscriptionDNA Damage and RepairSummaryProblems26Dr.Fu Qiang. Dept.of Biochem

33、istry & Molecular Biology, Preclinical Medicine School, SCU, 2006. 11Replication: Biosynthesis of DNABrief introduction:5TheprimaryfunctionofDNAreplicationisunderstood to be the provision of progeny with thegenetic information possessed by the parent. 3Replication is semiconservative, each strand ac

34、ting as template for a new daughter strand. It is carried5outinthreeidentifiablephases:initiation,elongation, and termination. The reaction starts atthe origin and usually proceeds bidirectionally.復(fù)制起點(diǎn)IntroductionFundamental RulesMajor enzymesProcessReverse TranscriptionDNA Damage and RepairSummaryP

35、roblems27Dr.Fu Qiang. Dept.of Biochemistry & Molecular Biology, Preclinical Medicine School, SCU, 2006. 11Replication: Biosynthesis of DNABrief introduction:5TheprimaryfunctionofDNAreplicationisunderstood to be the provision of progeny with thegenetic information possessed by the parent. 3Replicatio

36、n is semiconservative, each strand acting as template for a new daughter strand. It is carried5outinthreeidentifiablephases:initiation,elongation, and termination. The reaction starts atthe origin and usually proceeds bidirectionally.雙向地IntroductionFundamental RulesMajor enzymesProcessReverse Transc

37、riptionDNA Damage and RepairSummaryProblems28Dr.Fu Qiang. Dept.of Biochemistry & Molecular Biology, Preclinical Medicine School, SCU, 2006. 11Replication: Biosynthesis of DNABrief introduction:5DNA聚合酶TheprimaryfunctionofDNAreplicationisunderstood to be the provision of progeny with thegenetic inform

38、ation possessed by the parent. 3Replication is semiconservative, each strand acting as template for a new daughter strand. It is carried5outinthreeidentifiablephases:initiation,elongation, and termination. The reaction starts atthe origin and usually proceeds bidirectionally.Besides DNA polymerase,

39、DNA replication requires5many other enzymes and protein factors.IntroductionFundamental RulesMajor enzymesProcessReverse TranscriptionDNA Damage and RepairSummaryProblems29Dr.Fu Qiang. Dept.of Biochemistry & Molecular Biology, Preclinical Medicine School, SCU, 2006. 11Replication: Biosynthesis of DN

40、ABrief introduction:5DNAineachchromosomeisexactlyreplicatedaccording to the rules of base pairing during the Sphaseofthecellcycle.DNAsynthesisand replication are rigidly controlled.堿基配對(duì)原則IntroductionFundamental RulesMajor enzymesProcessReverse TranscriptionDNA Damage and RepairSummaryProblems30Dr.Fu

41、 Qiang. Dept.of Biochemistry & Molecular Biology, Preclinical Medicine School, SCU, 2006. 11Replication: Biosynthesis of DNABrief introduction:5DNAineachchromosomeisexactlyreplicatedaccording to the rules of base pairing during the Sphaseofthecellcycle.DNAsynthesisandreplication are rigidly controll

42、ed.DNA復(fù)制是受?chē)?yán)格調(diào)控的IntroductionFundamental RulesMajor enzymesProcessReverse TranscriptionDNA Damage and RepairSummaryProblems31Dr.Fu Qiang. Dept.of Biochemistry & Molecular Biology, Preclinical Medicine School, SCU, 2006. 11Replication: Biosynthesis of DNABrief introduction:5DNAineachchromosomeisexactly

43、replicatedaccording to the rules of base pairing during the Sphase of the cell cycle. DNA synthesis and replication are rigidly controlled.Maintaining the integrity of the information in DNA is a cellular imperative, supported by an elaborate set of DNA repair systems.5DNA修復(fù)體系IntroductionFundamental

44、 RulesMajor enzymesProcessReverse TranscriptionDNA Damage and RepairSummaryProblems32Dr.Fu Qiang. Dept.of Biochemistry & Molecular Biology, Preclinical Medicine School, SCU, 2006. 11Replication: Biosynthesis of DNABrief introduction:5DNAineachchromosomeisexactlyreplicatedaccording to the rules of ba

45、se pairing during the Sphase of the cell cycle. DNA synthesis and replication are rigidly controlled.Maintaining the integrity of the information in DNA is a cellular imperative, supported by an elaborate set of DNA repair systems.5Reversetranscriptaseproduces DNAfromviral5RNA.逆轉(zhuǎn)錄酶IntroductionFundam

46、ental RulesMajor enzymesProcessReverse TranscriptionDNA Damage and RepairSummaryProblems33Dr.Fu Qiang. Dept.of Biochemistry & Molecular Biology, Preclinical Medicine School, SCU, 2006. 11Replication: Biosynthesis of DNA10.1 Fundamental Rules of Replication IntroductionFundamental RulesMajor enzymesP

47、rocessReverse TranscriptionDNA Damage and RepairSummaryProblems34Dr.Fu Qiang. Dept.of Biochemistry & Molecular Biology, Preclinical Medicine School, SCU, 2006. 11Replication: Biosynthesis of DNA復(fù)制的基本規(guī)律IntroductionFundamental RulesMajor enzymesProcessReverse TranscriptionDNA Damage and RepairSummaryP

48、roblems10.1 Fundamental Rules of Replication35Dr.Fu Qiang. Dept.of Biochemistry & Molecular Biology, Preclinical Medicine School, SCU, 2006. 11Replication: Biosynthesis of DNA10.1 Fundamental Rules of Replication Contents:.210.1.3Semiconservative Replication. Bidirectional Replication.Semi

49、discontinuous Replication.IntroductionFundamental RulesMajor enzymesProcessReverse TranscriptionDNA Damage and RepairSummaryProblems36Dr.Fu Qiang. Dept.of Biochemistry & Molecular Biology, Preclinical Medicine School, SCU, 2006. 11Replication: Biosynthesis of DNAFundamental RulesSemiconservativeBidi

50、rectionalSemidiscontinuous10.1.1Semiconservative Replication37Dr.Fu Qiang. Dept.of Biochemistry & Molecular Biology, Preclinical Medicine School, SCU, 2006. 11Replication: Biosynthesis of DNA半保留復(fù)制Fundamental RulesSemiconservativeBidirectionalSemidiscontinuous10.1.1Semiconservative Replication38Dr.Fu

51、 Qiang. Dept.of Biochemistry & Molecular Biology, Preclinical Medicine School, SCU, 2006. 11Replication: Biosynthesis of DNAContents:1.2.3.Three possible ways of replication. DNA replication is semiconservative.The experimental confirmation of seminconservative replication.Significance4.Fundamental

52、RulesSemiconservativeBidirectionalSemidiscontinuous10.1.1Semiconservative Replication39Dr.Fu Qiang. Dept.of Biochemistry & Molecular Biology, Preclinical Medicine School, SCU, 2006. 11Replication: Biosynthesis of DNA1. Three possible ways of replication.Fundamental RulesSemiconservativeBidirectional

53、Semidiscontinuous40Dr.Fu Qiang. Dept.of Biochemistry & Molecular Biology, Preclinical Medicine School, SCU, 2006. 11Replication: Biosynthesis of DNA1. Three possible ways of replication.Theoretically, DNA could serve as its own template in one of three different ways:Fundamental RulesSemiconservativeBidirectionalSemidiscontinuous41Dr.Fu Qiang. Dept.of Biochemistry & Molecular Biology, Preclinical Medicine School, SCU, 2006. 11Replication: Biosynthesis of DNA1. Three possible ways of replication.Theoretica