分子生物學(xué)（楊洋）課程總結(jié)

1、整理課件The revised central dogmaTranslationRNA processingDNA repair基基因因組組的的保保持持基基因因組組的的表表達(dá)達(dá)regulation分子生物學(xué)技術(shù)分子生物學(xué)技術(shù)（原理及應(yīng)用）（原理及應(yīng)用）整理課件課程總結(jié)課程總結(jié) 第一章第一章-緒論，緒論，DNA和和RNA結(jié)構(gòu)結(jié)構(gòu) 第二章第二章-染色體，染色質(zhì)和核小體染色體，染色質(zhì)和核小體(Chromosomes, chromatin, and the nucleosome） 第三章第三章-DNA的復(fù)制的復(fù)制(The replication of DNA） 第四章第四章-DNA的突變和修復(fù)的突變和

2、修復(fù)(The mutability and repair of DNA） 第五章第五章-轉(zhuǎn)錄機(jī)制轉(zhuǎn)錄機(jī)制(Mechanisms of Transcription) 第六章第六章 RNA剪接剪接(RNA Splicing） 第七章第七章 翻譯翻譯-1，2, 3 第八章第八章-遺傳密碼遺傳密碼 (genetic code) 第九章第九章-分子生物學(xué)技術(shù)分子生物學(xué)技術(shù)(Techniques of molecular biology) 第十章第十章 原核生物基因表達(dá)調(diào)控原核生物基因表達(dá)調(diào)控(Regulation in prokaryotes) 第十一章第十一章 真核生物基因表達(dá)調(diào)控真核生物基因表達(dá)調(diào)控

3、(Regulation in eukaryotes) 第十二章第十二章-DNA重組重組整理課件第一章第一章-緒論，緒論，DNA和和RNA結(jié)構(gòu)結(jié)構(gòu) 分子生物學(xué)的含義分子生物學(xué)的含義 分子生物學(xué)的發(fā)展分子生物學(xué)的發(fā)展 分子生物學(xué)研究內(nèi)容分子生物學(xué)研究內(nèi)容 整理課件What is Molecular biology?Define in broadly: （廣義定義）（廣義定義）understand biological phenomena in molecular terms (difficult to distinguish from biochemistry)Define in restrict

4、ively: （狹義定義）（狹義定義）the study of gene structure and their activities in molecular level（分子水平上研究基因的結(jié)構(gòu)和功能）（分子水平上研究基因的結(jié)構(gòu)和功能）整理課件Gene concept Gene structureGene replication Gene expression Gene recombinationGene mutationMolecular Biology of Gene（基因的分子生物學(xué)）（基因的分子生物學(xué)）整理課件第二章第二章-染色體，染色質(zhì)和核小體染色體，染色質(zhì)和核小體(Chromo

5、somes, chromatin, and the nucleosome） Chromosome sequence & diversity（染色體序列和多樣性）（染色體序列和多樣性） The nucleosome（核小體）（核小體） Higher-order chromatin structure（染色質(zhì)的高級(jí)結(jié)構(gòu)）（染色質(zhì)的高級(jí)結(jié)構(gòu)） Regulation of chromatin structure（染色質(zhì)結(jié)構(gòu)的調(diào)控）（染色質(zhì)結(jié)構(gòu)的調(diào)控）整理課件Nucleosomes are the building blocks of chromosomes（核小體是染（核小體是染色體的結(jié)構(gòu)單位

6、）色體的結(jié)構(gòu)單位） 在真核細(xì)胞中大多數(shù)在真核細(xì)胞中大多數(shù)DNA被包裝進(jìn)被包裝進(jìn)核小體核小體 The nucleosome is composed of a core of eight histone proteins and the DNA (core DNA, 147 bp，核心，核心DNA) wrapped around them（核小體由（核小體由8個(gè)組蛋白所形成的核組成，個(gè)組蛋白所形成的核組成，DNA纏繞在組蛋白核上）纏繞在組蛋白核上） The DNA between each nucleosome is called a linker DNA（連接（連接DNA). Each euka

7、ryote has a characteristic average linker DNA length (20-60 bp)整理課件Figure 7-18 DNA packaged into nucleosomeSix-fold DNA compactionDNA盤繞在組蛋白核上盤繞在組蛋白核上（H2A, H2B, H3，H4）整理課件第三章第三章-DNA的復(fù)制的復(fù)制(The replication of DNA） 1. The Chemistry of DNA Synthesis(DNA合成合成的化學(xué)基礎(chǔ)）的化學(xué)基礎(chǔ)） 2. The Mechanism of DNA Polymerase（

8、DNA聚合酶的作用機(jī)制）聚合酶的作用機(jī)制） 3. The Specialization of DNA Polymerases（DNA聚合酶的特化）聚合酶的特化） 4. The Replication Fork（復(fù)制叉）（復(fù)制叉） 5. DNA Synthesis at the Replication Fork（復(fù)（復(fù)制叉上的制叉上的DNA合成）合成） 6. Initiation of DNA Replication（復(fù)制的起始）（復(fù)制的起始） 7. Binding and Unwinding（結(jié)合和解旋）（結(jié)合和解旋） 8. Finishing Replication（復(fù)制的終止）（復(fù)制的終止

9、）整理課件The Chemistry of DNA Synthesis: substrate, direction and energy. The Mechanism of DNA Polymerase: 1 polymerization mechanism, 2 different ways of discriminating substrates, 2 catalytic sites; 3 domains.The Specialization of DNA PolymerasesThe Replication Fork: the enzyme/proteins required to sy

10、nthesize the leading and lagging strands.DNA Synthesis at the Replication Fork: Holoenzyme/trombone model to explain how the anti-parallel template strands are copied/replicated toward the replication fork. Replisome/protein interaction.Summary整理課件Initiation of DNA Replication/binding and unwinding:

11、 the replicon model; initiation in bacteria; initiation control in eukaryotes-a link with cell cycle (pre-RC assembly and activation). Finishing Replication: Telomeres, telomerase整理課件 整理課件DNA Polymerase The polymerase chain reaction(PCR) is to used to amplify a sequence of DNA in vitro, using a pair

12、 of primers each complementary to one end of the the DNA target sequence.復(fù)制理論復(fù)制理論實(shí)驗(yàn)技術(shù)實(shí)驗(yàn)技術(shù)整理課件Denaturation (變性變性): The target DNA (template) is separated into two stands by heating to 95Primer annealing (退火退火): The temperature is reduced to around 55 to allow the primers to anneal.Polymerization (elo

13、ngation, extension) (延伸延伸): The temperature is increased to 72 for optimal polymerization step which uses dNTPs and requires Mg+.The principle of PCR:Three different steps proceed in each PCR cycle. 整理課件Reverse transcriptase (RT)-PCR逆轉(zhuǎn)錄逆轉(zhuǎn)錄PCRAAA(A)n5-CapmRNA(dT)1218 primeranneal5-CapAAA(A)n35Reverse

14、 transcriptiondNTP, RT5-CapAAA(A)n5cDNA:mRNA hybridRegularPCR整理課件第四章第四章-DNA的突變和修復(fù)的突變和修復(fù)(The mutability and repair of DNA）Replication errors and their repair (復(fù)復(fù)制錯(cuò)誤及其修復(fù)）制錯(cuò)誤及其修復(fù)）DNA damage （DNA損傷）損傷）Repair of DNA damage（DNA損傷的修損傷的修復(fù)）復(fù)）整理課件 復(fù)制中產(chǎn)生的錯(cuò)誤以及它們是如何被修復(fù)的復(fù)制中產(chǎn)生的錯(cuò)誤以及它們是如何被修復(fù)的 自發(fā)產(chǎn)生或來自外界的攻擊造成的各種損傷自發(fā)產(chǎn)生

15、或來自外界的攻擊造成的各種損傷 細(xì)胞修復(fù)損傷的多種修復(fù)機(jī)制細(xì)胞修復(fù)損傷的多種修復(fù)機(jī)制生物在保持遺傳物質(zhì)忠實(shí)性方面的努力生物在保持遺傳物質(zhì)忠實(shí)性方面的努力整理課件復(fù)制中產(chǎn)生的錯(cuò)誤以及它們是如何被修復(fù)的復(fù)制中產(chǎn)生的錯(cuò)誤以及它們是如何被修復(fù)的自發(fā)產(chǎn)生或來自外界的攻擊造成的各種損傷自發(fā)產(chǎn)生或來自外界的攻擊造成的各種損傷DNA損傷的各種類型損傷的各種類型細(xì)胞修復(fù)細(xì)胞修復(fù)DNA損傷的多種修復(fù)機(jī)制：損傷的多種修復(fù)機(jī)制： 1. Direct reversal of DNA damage by photoreactivation (光活化作光活化作用用) and alkyltransferase (烷基轉(zhuǎn)移酶烷

16、基轉(zhuǎn)移酶)-直接將損傷逆轉(zhuǎn)直接將損傷逆轉(zhuǎn) 2. 剪切修復(fù)系統(tǒng)（剪切修復(fù)系統(tǒng)（excision repair system)： 僅僅將受損的核苷酸去除僅僅將受損的核苷酸去除 將包含損傷的一小段單鏈將包含損傷的一小段單鏈DNA去除去除 3. 重組修復(fù)系統(tǒng)（重組修復(fù)系統(tǒng)（Recombination repair）：當(dāng)）：當(dāng)DNA兩條鏈都受損兩條鏈都受損（斷裂）時(shí)采用這種修復(fù)（斷裂）時(shí)采用這種修復(fù)雙鏈斷裂修復(fù)（雙鏈斷裂修復(fù)（ Double-strand break repair） 4. 移損移損DNA合成（合成（Translesion DNA synthesis）：）：DNA聚合酶的復(fù)聚合酶的復(fù)制進(jìn)程

17、被受損堿基阻礙時(shí)采用的修復(fù)制進(jìn)程被受損堿基阻礙時(shí)采用的修復(fù)整理課件1. Direct reversal of DNA damage by photoreactivation (光活化作用光活化作用) and alkyltransferase (烷基轉(zhuǎn)移酶烷基轉(zhuǎn)移酶)-直接將損傷逆轉(zhuǎn)直接將損傷逆轉(zhuǎn)2. 剪切修復(fù)系統(tǒng)（剪切修復(fù)系統(tǒng)（excision repair system)：另一條未：另一條未受損的鏈作為模板，以便受損的鏈作為模板，以便DNA聚合酶重新?lián)饺胝_的核苷酸聚合酶重新?lián)饺胝_的核苷酸僅僅將受損的核苷酸去除僅僅將受損的核苷酸去除將包含損傷的一小段單鏈將包含損傷的一小段單鏈DNA去除去除

18、3. 重組修復(fù)系統(tǒng)（重組修復(fù)系統(tǒng)（Recombination repair）：當(dāng)）：當(dāng)DNA兩條鏈都受損（斷裂）時(shí)采用這種修復(fù)兩條鏈都受損（斷裂）時(shí)采用這種修復(fù)雙鏈斷裂修復(fù)雙鏈斷裂修復(fù)（ Double-strand break repair）4. 移損移損DNA合成（合成（Translesion DNA synthesis）：）：DNA聚合酶的復(fù)制進(jìn)程被受損堿基阻礙時(shí)采用的修復(fù)聚合酶的復(fù)制進(jìn)程被受損堿基阻礙時(shí)采用的修復(fù)Mechanisms to repair a damage（DNA損傷的修復(fù)系統(tǒng)）損傷的修復(fù)系統(tǒng)）整理課件第五章第五章-轉(zhuǎn)錄機(jī)制轉(zhuǎn)錄機(jī)制(Mechanisms of Transc

19、ription)n RNA polymerase and the transcription cycle（RNA聚合酶和轉(zhuǎn)錄周期）n The transcription cycle in bacteria（細(xì)菌的轉(zhuǎn)錄周期）n Transcription in eukaryotes（真核生物的轉(zhuǎn)錄）整理課件RNA polymerases (RNAP, 真核和原核的異同真核和原核的異同) and transcription cycle (Initiation, elongation and termination)Transcription cycle in bacteria: -Initiati

20、on: (1) The feature of s s70 promoters. (2) Promoter binding by s s70 transcription factor (recognition mechanism). (3) Transition to open complex. (4) Promoter escape and transition to the ternary complex. -Elongation and editing by polymerase-Termination: Rho-independent and Rho-dependent mechanis

21、m.整理課件Transcription in eukaryotes by RNAP II: -Initiation(i) Cis-acting elements: core promoter & regulatory sequences(ii) Formation of the pre-initiation complex(iii) Promoter escape and the CTD tail(iv) The function of each GTF (in vitro)(v) Additional proteins for in vivo transcription. -Elon

22、gation and proofreading involve a new set of GTFs -Coupled with RNA processing -5 capping and 3 polyadenylation (mechanisms)-Termination整理課件4. Transcription in eukaryotes by RNAP I and III-initiation: Promoter binding and formation of the closed complex.整理課件第六章第六章 RNA剪接剪接(RNA Splicing）整理課件Figure 13-

23、1Primary transcript外顯子外顯子內(nèi)含子內(nèi)含子前前mRNA剪接后的剪接后的mRNA整理課件 RNA剪接的化學(xué)基礎(chǔ)剪接的化學(xué)基礎(chǔ) 剪接體剪接體 剪接過程剪接過程 可變剪接可變剪接 自剪接內(nèi)含子自剪接內(nèi)含子 RNA編輯編輯 mRNA轉(zhuǎn)運(yùn)轉(zhuǎn)運(yùn)整理課件Why RNA splicing is important? Chemical reaction: determination of the splice sites, the products, trans-splicingSpliceosome: splicing pathway and finding the splice site

24、s.Self-splicing introns and mechanismsAlternative splicing and regulationTwo different mechanisms of RNA editingmRNA transport-a link to translation 整理課件第七章第七章 翻譯翻譯-1，2, 3Topic 1-4: Four components of translation machinerymRNA tRNA attachment of amino acids to tRNA (aminoacyl-tRNA synthetases) ribos

25、omeTopic 5-7: Translation processinitiation; elongation; terminationTopic 8: Antibiotics ( (抗生素）抗生素）and translation整理課件2/6/202229Basic machinery of TranslationnmRNAs (5% of total cellular RNA)-message RNAntRNAs (15%)-transfer RNAnaminoacyl-tRNA synthetases (氨酰tRNA合成酶)nribosomes (核糖體): rRNA整理課件Overvi

26、ew of the events of translationTermination Elongation Initiation整理課件Three events must occur:ribosome must be recruited to mRNA2. a charged tRNA must be placed into the P site of ribosome3. the ribosome must be precisely positioned over the start codon整理課件Three initiation factors (IF) direct the asse

27、mbly of an initiation complex that contains mRNA and initiator tRNA Translation initiation factors (IF):IF1: prevent tRNA from binding to the A site in the small subunitIF2: a GTPase that interacts with small subunit, IF1 and initiator tRNA (fMet-tRNAfMet); IF2 can facilitate the association of fMet

28、-tRNAfMet with the small subunitIF3: binds to the small subunit and blocks it from reassociating with large subunit, helps to dissociate the 70S ribosome into its large and small subunit整理課件進(jìn)位進(jìn)位易位易位肽鍵形成肽鍵形成整理課件Two classes of release factors Class I: recognize the stop codon and trigger hydrolysis of

29、 the polypeptide from peptidyl-tRNA Prokaryotes: RF1-UAG,UAA RF2-UGA,UAA Eukaryotes: eRF1-UAG,UGA,UAA Class II: stimulate the dissociation of the class I factors from the ribosome after release of polypeptide Prokaryotes: RF3 Eukaryotes: eRF3 GTP-binding protein 整理課件 Antibiotics ( (抗生素）抗生素）and trans

30、lationPuromycin (嘌呤霉素嘌呤霉素)Puromycin resembles the aminoacylated-tRNA, so it can bind to the A site of ribosome 整理課件Puromycin (嘌呤霉素嘌呤霉素)肽酰嘌呤霉素肽酰嘌呤霉素(peptidyl-puromycin)Puromycin整理課件第八章第八章-遺傳密碼遺傳密碼 (genetic code)1 遺傳密碼的破譯遺傳密碼的破譯2 遺傳密碼的特征與性質(zhì)遺傳密碼的特征與性質(zhì)3 遺傳密碼的簡并性和擺動(dòng)假說遺傳密碼的簡并性和擺動(dòng)假說4 改變遺傳密碼的幾類突變改變遺傳密碼的幾類突變

31、 4.1 錯(cuò)義突變錯(cuò)義突變 4.2 無義突變無義突變 4.3 移碼突變移碼突變5 基因內(nèi)抑制突變和基因間抑制突變基因內(nèi)抑制突變和基因間抑制突變6 遺傳密碼的通用性遺傳密碼的通用性整理課件“The genetic code is degenerate” What does it mean? What are the benefits?What is the wobble concept? How the wobble in the anticodon affect the number of tRNAs to recognize the 61 codons?What are the mutati

32、ons altering genetic code? What are suppressor mutations? What is the difference between intragenic suppression and intergenic suppression?What are the benefits of the code universality? 整理課件Intergenic Suppression Involves mutant tRNAsMutant tRNA genes suppress the effects of nonsense mutations in p

33、rotein-coding genes. They act by reading a stop codon as if it were a signal for a specific amino acid.整理課件第九章第九章-分子生物學(xué)技術(shù)分子生物學(xué)技術(shù)(Techniques of molecular biology)DNA-Basic principleBasic procedure application整理課件 Separation by Electrophoresis (電泳分離電泳分離) Cut by Restriction endonuclease (限制性限制性內(nèi)切酶切割技術(shù)內(nèi)

34、切酶切割技術(shù)) DNA Cloning and gene expression (基因基因克隆和表達(dá)技術(shù)）克隆和表達(dá)技術(shù)） 分子雜交技術(shù)（分子雜交技術(shù)（ Southern Northern PCR技術(shù)（聚合酶鏈?zhǔn)椒磻?yīng)）技術(shù)（聚合酶鏈?zhǔn)椒磻?yīng)）整理課件Restriction digestion of your insert and vector using the same enzyme.Use ligase (連接酶）連接酶） to join your insert and vector together.Transform the ligation products into E. coli

35、competent cells.Select the desired clones: Grow the cells on a plate containing tetracycline (四環(huán)素四環(huán)素).EcoRI整理課件 Protein purification (蛋白質(zhì)純化蛋白質(zhì)純化) Affinity chromatography can facilitate more rapid protein purification (親和層析親和層析純化純化) Protein separation by PAGE gel electrophoresis (蛋白質(zhì)分離蛋白質(zhì)分離) and iden

36、tification by Western analysis(免疫免疫印跡印跡)整理課件 （一）DNA-protein affinity chromatography (DNA-蛋白親和層析) (二）Gel retardation (凝膠阻滯, EMSA，競爭性 EMSA) （三）DNase I footprinting (DNase I 足跡法) （四）染色質(zhì)免疫共沉淀技術(shù)（chromatin immunoprecipitation assay, CHIP） -研究體內(nèi)DNA與蛋白質(zhì)相互作用的方法 （五）Yeast one-hybrid system(酵母單雜交)整理課件- Yeast tw

37、o-hybrid system(酵母雙雜交酵母雙雜交) 免疫共沉淀技術(shù)免疫共沉淀技術(shù)整理課件targetbait No transcriptiontargetbait XYbaitpredatorcDNA for Xyeast plasmidexpression vectortransformedyeastFishing with the yeast two-hybrid systembait targetdoes X bindwith a unknownprotein?protein Xbaittranscription machineryXYbaitpreylac 2-galactosid

38、aseX-galblue colorBDAD DNA-bindingdomainBDXBDcDNA library+AD fusion plasmid transform整理課件Libraries of DNA molecules can be created by cloning (Genomic library and cDNA library) (DNA文庫文庫) is a population of identical vectors that each contains a different DNA insert. (基因組文庫基因組文庫) : the DNA inserts in

39、 a DNA library is derived from restriction digestion of the genomic DNA. (cDNA文庫文庫) : the DNA inserts in a DNA library is converted from the mRNAs of a tissue, a cell type or an organism. cDNA stands for the DNA copied from mRNA. 整理課件Proteomics (蛋白質(zhì)組學(xué)蛋白質(zhì)組學(xué))Three principle methods 1. 2-D gel electrop

40、horesis for (蛋白質(zhì)分離蛋白質(zhì)分離). 2. MS spectrometry for the precise of the molecular weight and identify of a protein (蛋白質(zhì)鑒定蛋白質(zhì)鑒定). 3. Bioinformatics for proteins and peptides to the predicted protein coding sequence in the genome (蛋白質(zhì)蛋白質(zhì)確定確定).整理課件 原理機(jī)制原理機(jī)制 應(yīng)用應(yīng)用RNA干擾技術(shù)干擾技術(shù)（RNA interference, RNAi） 整理課件第十章第十

41、章 原核生物基因表達(dá)調(diào)控原核生物基因表達(dá)調(diào)控(Regulation in prokaryotes) TOPIC 1 Principles of Transcriptional Regulation TOPIC 2 Regulation of Transcription Initiation: Examples from Bacteria (Lac operon,乳糖操縱子乳糖操縱子) TOPIC 3 Examples of Gene Regulation after Transcription Initiation (Trp operon，色氨酸操縱子，色氨酸操縱子) （基于可變（基于可變s

42、s因子的全局性調(diào)控）因子的全局性調(diào)控）整理課件TOPIC 1 Principles of Transcriptional Regulation Gene expression is controlled at different stages (基基因表達(dá)調(diào)控可以發(fā)生在不同時(shí)期因表達(dá)調(diào)控可以發(fā)生在不同時(shí)期): The key step of gene regulation takes place at the initiation of transcription Gene Expression is Controlled by Regulatory Proteins (調(diào)控蛋白調(diào)控蛋白) P

43、ositive regulators or activators Negative regulators or repressors recruitment regulation (招募調(diào)控招募調(diào)控) Allostery regulation (異構(gòu)調(diào)控異構(gòu)調(diào)控): converts the closed complex to open complex Basic principle of regulation of gene expression: Interaction between trans-acting factor (regulatory protein) and cis-act

44、ing element (control element):反式反式作用因子和順式作用元件作用因子和順式作用元件 整理課件Control elementStructural genesBasic principle of regulation of gene expression:Interaction between trans-acting factor (regulatory protein) and cis-acting element (control element) 反式作用因子和順式作用元件之間的相互作用反式作用因子和順式作用元件之間的相互作用trans-acting fact

45、or整理課件TOPIC 2 Regulation of Transcription Initiation: Examples from Bacteria (Lac operon) Structural genes Control elements, such as operator(sequence Regulator gene整理課件a unit of prokarytoic gene expression and regulation which typically includes: 1. Structural genes for enzymes in a specific biosyn

46、thetic pathway whose expression is coordinately controlled 2. Control elements, such as operator(sequence-cis-acting element 3. Regulator gene(s) code for regulatory protein which can recognize and interact with the control elements整理課件 Negative control of the Lac operon: interaction between repress

47、or and operator (乳糖操縱子負(fù)調(diào)控乳糖操縱子負(fù)調(diào)控)Two key elements: lacI: encoding lac repressor, trans-acting factor operator: lac repressor binding site, cis-acting element整理課件lacIpromoterRNA polymeraselacZlacYlacANo transcriptiontranscriptionoperatoractive repressorinactive repressor阻遏阻遏去阻遏去阻遏整理課件 Positive contr

48、ol of the Lac operon: interaction between CAP-cAMP complex and CAP binding site (乳糖操縱子正調(diào)控乳糖操縱子正調(diào)控) CAP (Catabolite Activator Protein, 代謝產(chǎn)物代謝產(chǎn)物激活蛋白激活蛋白) or CRP (cAMP Receptor Protein, cAMP受體蛋白受體蛋白) the CAP-cAMP binding site整理課件MechanismCAP-cAMPCAP binding sitelacZTranscription（轉(zhuǎn)錄）（轉(zhuǎn)錄）促進(jìn)了促進(jìn)了RNA聚合酶和啟動(dòng)子

49、結(jié)合形成穩(wěn)定的開放復(fù)合體聚合酶和啟動(dòng)子結(jié)合形成穩(wěn)定的開放復(fù)合體(RNA聚合酶聚合酶)(啟動(dòng)子啟動(dòng)子)整理課件The LAC operon整理課件 TOPIC 3 Examples of Gene Regulation after Transcription Initiation (Trp operon)Two layers of regulation are involved: (1) transcription repression by the Trp repressor (阻遏作用阻遏作用)-粗調(diào)粗調(diào)(2) attenuation(衰減作用衰減作用)-細(xì)調(diào)細(xì)調(diào)整理課件Transcript

50、ion repression by the Trp repressor (阻遏作用阻遏作用) -粗調(diào)粗調(diào)低色氨酸低色氨酸: 去阻遏去阻遏高色氨酸高色氨酸: 阻遏阻遏inactive repressoractive repressorNo transcription整理課件色氨酸色氨酸14個(gè)氨基酸的前導(dǎo)肽個(gè)氨基酸的前導(dǎo)肽整理課件Low TrpHigh TrpFig 16-21Complementary 2:3 Elongation of transcription Complementary 3:4 termination of transcription整理課件 （基于可變（基于可變s s因子

51、的全局性調(diào)控）因子的全局性調(diào)控） 整理課件細(xì)菌經(jīng)歷逆境：饑餓，熱激，缺氮；枯草芽孢細(xì)菌經(jīng)歷逆境：饑餓，熱激，缺氮；枯草芽孢桿菌的孢子形成等桿菌的孢子形成等細(xì)菌通過轉(zhuǎn)錄的全局性變化對(duì)其環(huán)境變化作出細(xì)菌通過轉(zhuǎn)錄的全局性變化對(duì)其環(huán)境變化作出應(yīng)答，這些全局性的轉(zhuǎn)錄變化是通過應(yīng)答，這些全局性的轉(zhuǎn)錄變化是通過RNA聚合聚合酶的變化得以實(shí)現(xiàn)的酶的變化得以實(shí)現(xiàn)的整理課件整理課件 RNA聚合酶的變化本質(zhì)上是因子的變化因子的變化， 因子控制轉(zhuǎn)錄的特異性細(xì)菌通過轉(zhuǎn)錄的全局性變化對(duì)其環(huán)境變化作出細(xì)菌通過轉(zhuǎn)錄的全局性變化對(duì)其環(huán)境變化作出應(yīng)答，這些全局性的轉(zhuǎn)錄變化是通過應(yīng)答，這些全局性的轉(zhuǎn)錄變化是通過RNA聚合聚合酶的變

52、化得以實(shí)現(xiàn)的酶的變化得以實(shí)現(xiàn)的整理課件第十一章第十一章 真核生物基因表達(dá)調(diào)控真核生物基因表達(dá)調(diào)控(Regulation in eukaryotes) TOPIC 1: Principles of Regulation in eukaryotes Topic 2Transcription factors Topic 3: chromatin structure and its effect on transcription Topic 4 repressors整理課件TOPIC 1 Principles of Regulation in eukaryotes Similarity of regu

53、lation between eukaryotes and prokaryote Difference in regulation between eukaryotes and prokaryote整理課件Difference in regulation between eukaryotes and prokaryotePre-mRNA splicing adds an important step for regulation. (intron, extron, mRNA前體的剪接前體的剪接)The eukaryotic transcriptional machinery is more e

54、laborate than its bacterial counterpart. (真核轉(zhuǎn)錄機(jī)器更復(fù)雜真核轉(zhuǎn)錄機(jī)器更復(fù)雜, transcription factors)Nucleosomes and their modifiers influence access to genes. (核小體及其修飾體核小體及其修飾體) 1. Many eukaryotic genes have more regulatory binding sites and are controlled by more regulatory proteins than are bacterial genes. (真核基因

55、有更多真核基因有更多調(diào)控蛋白調(diào)控蛋白結(jié)合位點(diǎn)結(jié)合位點(diǎn)) 整理課件TOPIC 2 Transcription factorsGeneral transcription factors: Basal level transcriptionGene-specific transcription factors (activator)整理課件 Eukaryotic activators (真核激活蛋白真核激活蛋白) have separate DNA binding and activating functions: contains separate DNA binding and activati

56、ng domains The based on the separation of DNA binding and activating domains is used to identify proteins interacting with each other整理課件Eukaryotic activators (真核激活蛋白真核激活蛋白) also work by recruiting (招募招募) as in bacteria Eukaryotic activators recruit polymerase indirectly in two ways:1. Interacting w

57、ith parts of the transcription machinery except for RNA polymerase.2. Recruiting nucleosome modifiers that alter chromatin in the vicinity of a gene.整理課件The contains polymerase and numerous proteins being organized to several complexes, such as the Mediator and the TFD complex. Activators interact w

58、ith one or more of these complexes and recruit them to the promoter.Figure 17-9整理課件 Nucleosomes are the building blocks of chromosomes Histones are small, positively charged (basic) proteins The core histones each have an N-terminal “tail”, the sites of extensive modifications Histone not only is th

59、e structural component of nucleosome, but also can regulate the gene expression整理課件 histone modification such as acetylation（組蛋白乙?；福ńM蛋白乙酰化酶） 整理課件整理課件整理課件 repressorsIn eukaryotes, most repressors repress transcription by binding to sites that overlap with the promoter and thus block binding of poly

60、merase. (Bacteria often do so)整理課件Commonly, eukaryotic repressors that compact the nucleosome or remove the groups recognized by the transcriptional machinery Contrast to the activator recruited nucleosome modifers, histone deacetylases (組蛋白去乙酰組蛋白去乙?；富? repress the transcription by removing the acetyl gro