武汉大学生命科学学院：《分子生物学》（英文版）Welcome Each of You to My Molecular Biology Class

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 a (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)