武汉大学生命科学学院：《分子生物学》英文版 CHAPTER 13 RNA Splicing

Welcome each of you to Molecular Biology Class 博来字 Wuhan universi

Welcome Each of You to My Molecular Biology Class

Molecular Biology of the Gene, 5/E --- Watson et al (2004) Part I: Chemistry and Genetics Part II: Maintenance of the Genome Part III: Expression of the Genome Part IV: Regulation Part v: methods 4/3/05 @博来穹

Molecular Biology of the Gene, 5/E --- Watson et al. (2004) Part I: Chemistry and Genetics Part II: Maintenance of the Genome Part III: Expression of the Genome Part IV: Regulation Part V: Methods 4/3/05

ch 12: Mechanisms of Transcription Ch 13: RNA Splicing Ch 14: Translation Ch 15: The enetic code 4/3/05 Wuhan University

Ch 12 : Mechanisms of Transcription Ch 13 : RNA Splicing Ch 14 : Translation Ch 15 : The Genetic code 4/3/05

Molecular iology course CHAPTER 13 RNA Splicing 博字 Wuhan University

CHAPTER 13 RNA Splicing •Molecular Biology Course

promoter region intron 1 2 genomIc DNA exon 1 transcription noncoding 5 leader region 4「1 pre-mRNA 5 3 Primary transcript splicing spliced mRNA 5 3′ Figure 13-1

Figure 13-1 Primary transcript

Most of the eukaryotic genes are mosaIc(嵌合体), consisting of intervening sequences separating the coding sequence Exons(外显子): the coding sequences Introns(内含子): the intervening sequences RNA splicing: the process by which introns are removed from the pre mRNA Alternative splicing〔可变剪接):some pre-mRNAs can be spliced in more than one way, generating alternative mRNAS. 60%o of the human genes are spliced in this manner

Most of the eukaryotic genes are mosaic (嵌合体), consisting of intervening sequences separating the coding sequence ◼ Exons (外显子): the coding sequences ◼ Introns (内含子) : the intervening sequences ◼ RNA splicing: the process by which introns are removed from the pre￾mRNA. ◼ Alternative splicing (可变剪接): some pre-mRNAs can be spliced in more than one way , generating alternative mRNAs. 60% of the human genes are spliced in this manner

CHAPTER 13 RNA Splicing Topic 1 THE CHEMISTRY OF RNA SPLICING

Topic 1 : THE CHEMISTRY OF RNA SPLICING CHAPTER 13 RNA Splicing

Sequences within the RNA Determine Where Splicing 6 Occurs The borders between introns and exons are marked by specific nucleotide sequences within the pre-mRNAS

Sequences within the RNA Determine Where Splicing Occurs The chemistry of RNA splicing The borders between introns and exons are marked by specific nucleotide sequences within the pre-mRNAs

5 exon intron exon 5 AGGUGAGU…A…[ Py tract]AGG3 5 splice site branch site 3 splice site The consensus sequences for human Figure 13-2 Copyright o 2004 Pearson Education, Inc, publishing as Benjamin Cummings

Figure 13-2 The consensus sequences for human

5 splice site(5剪接位点): the exon- intron boundary at the 5 end of the intron 3’ splice site(3剪接位点):the exon-intron boundary at the 3 end of the intron Branch point site(分枝位点):anA close to the 3 end of the intron which is followed by a polypyrimidine tract(Py tract)

◼ 5’splice site (5’剪接位点): the exon￾intron boundary at the 5’ end of the intron ◼ 3’ splice site (3’剪接位点): the exon-intron boundary at the 3’ end of the intron ◼ Branch point site (分枝位点): an A close to the 3’ end of the intron, which is followed by a polypyrimidine tract (Py tract)