dna replication molecular biology – dna replication, transcription
TRANSCRIPT
DNA REPLICATION
MOLECULAR BIOLOGY – DNA replication, transcription
Figure 5-2 Molecular Biology of the Cell (© Garland Science 2008)
MOLECULAR BIOLOGY – DNA replication, transcription
REPLICATION FORK
1000 nt / sec !
Figure 5-14 Molecular Biology of the Cell (© Garland Science 2008)
Unwinding and strand separation by DNA helicase
MOLECULAR BIOLOGY – DNA replication, transcription
Figure 5-16 Molecular Biology of the Cell (© Garland Science 2008)
MOLECULAR BIOLOGY – DNA replication, transcription
Figure 5-3 Molecular Biology of the Cell (© Garland Science 2008)
MOLECULAR BIOLOGY – DNA replication, transcription
UDP deoxyUDP dTTPADP deoxyADP dATPGDP deoxyGDP dGTPCDP deoxyCDP dCTP
dTDP
ribonucleotidereductase
kinase
Methotrexateanti-cancer drug
MOLECULAR BIOLOGY – DNA replication, transcription
Figure 5-18c Molecular Biology of the Cell (© Garland Science 2008)
DNA polymerase III
MOLECULAR BIOLOGY – DNA replication, transcription
replication direction
3’
3’
5’
5’
3’leading strand
3’5’
5’ 5’3’
lagging strandwith Okazaki
fragments
DNA polymerase synthesizes in 5’ 3’ direction
MOLECULAR BIOLOGY – DNA replication, transcription
Figure 5-11 Molecular Biology of the Cell (© Garland Science 2008)
DNA polymerase can’tstart a new strand, it can only elongate from existing one
(RNA polymerase can)
MOLECULAR BIOLOGY – DNA replication, transcription
Figure 5-12 Molecular Biology of the Cell (© Garland Science 2008)
polymerase I
MOLECULAR BIOLOGY – DNA replication, transcription
Figure 5-19a Molecular Biology of the Cell (© Garland Science 2008)
MOLECULAR BIOLOGY – DNA replication, transcription
Figure 5-19b,c Molecular Biology of the Cell (© Garland Science 2008)
MOLECULAR BIOLOGY – DNA replication, transcription
Figure 5-21 Molecular Biology of the Cell (© Garland Science 2008)
MOLECULAR BIOLOGY – DNA replication, transcription
Figure 5-22 Molecular Biology of the Cell (© Garland Science 2008)
MOLECULAR BIOLOGY – DNA replication, transcription
Figure 5-6 Molecular Biology of the Cell (© Garland Science 2008)
MOLECULAR BIOLOGY – DNA replication, transcription
Figure 5-25 Molecular Biology of the Cell (© Garland Science 2008)
MOLECULAR BIOLOGY – DNA replication, transcription
Figure 5-26 Molecular Biology of the Cell (© Garland Science 2008)
MOLECULAR BIOLOGY – DNA replication, transcription
Figure 5-34 Molecular Biology of the Cell (© Garland Science 2008)
MOLECULAR BIOLOGY – DNA replication, transcription
Problem with the end of the lagging strand:
... progressive shortening of chromosomal ends
TTAGGGTTAGGGTTAGGGTTAGGG
(TTAGGG)20-HUNDREDS
TELOMERES made of repeatsSpecies Repeat Sequence
Arabidopsis TTTAGGG
Human TTAGGG
Oxytricha TTTTGGGG
Slime Mold TAGGG
Tetrahymena TTGGGG
Trypanosome TAGGG
Yeast (TG)1-3TG2-3
MOLECULAR BIOLOGY – DNA replication, transcription
Figure 5-41 Molecular Biology of the Cell (© Garland Science 2008)
TELOMERES ELONGATED BY ACTION OF TELOMERASE
MOLECULAR BIOLOGY – DNA replication, transcription
Drosophila uses a different mechanism – transposition of retrotransposons Het-A and TART
Harald Biessmann
MOLECULAR BIOLOGY – DNA replication, transcription
~ 150 genes control the telomere length in yeast shortening telomeres associated with senescence
telomerase highly active in >90% of tumors
many adult cell types have detectable telomerase activity,it is highly regulated, fine tuned activity
MOLECULAR BIOLOGY – DNA replication, transcription
TAKE IT EASY TO KEEP YOUR TELOMERES LONG!
MOLECULAR BIOLOGY – DNA replication, transcription
PROMOTER
AATAAA
exon 1 exon 2 exon 3
ATG TAA
AAUAAAAUG UAA
AAUAAAAUG UAA
intron intron
TRANSCRIPTION
Pre-mRNA
mRNA
DNA
RNA SPLICING
protein
TRANSLATION
coding sequence
MAPSSRGG…..
5’ 3’
3’ 5’
ATGAGA
TACTCT
TACTCTATGAGA
RNAtemplate strand
OPEN READING FRAME
coding strand
5’UTR 3’UTR
CAP AAAAA
NUCLEUS
CYTOPLASM
UPSTREAM DOWNSTREAM
MOLECULAR BIOLOGY – DNA replication, transcription
Figure 6-21 Molecular Biology of the Cell (© Garland Science 2008)
MOLECULAR BIOLOGY – DNA replication, transcription
Figure 6-22a Molecular Biology of the Cell (© Garland Science 2008)
MOLECULAR BIOLOGY – DNA replication, transcription
Table 6-1 Molecular Biology of the Cell (© Garland Science 2008)
MOLECULAR BIOLOGY – DNA replication, transcription
TRANSCRIPTION INITIATION
MOLECULAR BIOLOGY – DNA replication, transcription
Figure 6-11 (part 1 of 7) Molecular Biology of the Cell (© Garland Science 2008)
TRANSCRIPTION START IN PROCARYOTES
MOLECULAR BIOLOGY – DNA replication, transcription
Figure 6-12a Molecular Biology of the Cell (© Garland Science 2008)
GENE
+1
PROMOTER
MOLECULAR BIOLOGY – DNA replication, transcription
5’ 3’
3’ 5’
ATGAGA
TACTCT
TACTCTATGAGA
RNAtemplate strand
coding strand
TERMINATOR
MOLECULAR BIOLOGY – DNA replication, transcription
Figure 6-9 Molecular Biology of the Cell (© Garland Science 2008)
MOLECULAR BIOLOGY – DNA replication, transcription
Table 6-2 Molecular Biology of the Cell (© Garland Science 2008)
MOLECULAR BIOLOGY – DNA replication, transcription
Table 6-3 Molecular Biology of the Cell (© Garland Science 2008)
MOLECULAR BIOLOGY – DNA replication, transcription
Figure 6-19 Molecular Biology of the Cell (© Garland Science 2008)
CORE PROMOTER
MOLECULAR BIOLOGY – DNA replication, transcription
RNA PROCESSING in Eukaryotes
AAUAAAAUG UAA
AAUAAAAUG UAA
intron intron
Pre-mRNA
mRNA
RNA SPLICING
5’UTR 3’UTR
CAP AAAAA
MOLECULAR BIOLOGY – DNA replication, transcription
Figure 6-22b Molecular Biology of the Cell (© Garland Science 2008)
Capping Eukaryotic mRNA
MOLECULAR BIOLOGY – DNA replication, transcription
Figure 6-38 Molecular Biology of the Cell (© Garland Science 2008)
MOLECULAR BIOLOGY – DNA replication, transcription
SPLICEOSOME
small nuclear RNA (snRNA)+
proteins=
small nuclear ribonucleoprotein … snRNP (“snurp”) U1-U6
MOLECULAR BIOLOGY – DNA replication, transcription
Figure 6-28 Molecular Biology of the Cell (© Garland Science 2008)
snRNAs of snurps recognize 3 sequences
5’ splice site branch site 3’ splice site
MOLECULAR BIOLOGY – DNA replication, transcription
Figure 6-26a Molecular Biology of the Cell (© Garland Science 2008)
MOLECULAR BIOLOGY – DNA replication, transcription
Figure 6-29 Molecular Biology of the Cell (© Garland Science 2008)
MOLECULAR BIOLOGY – DNA replication, transcription
Figure 6-30c Molecular Biology of the Cell (© Garland Science 2008)
MOLECULAR BIOLOGY – DNA replication, transcription
Figure 6-36 Molecular Biology of the Cell (© Garland Science 2008)
MOLECULAR BIOLOGY – DNA replication, transcription
Figure 6-31 Molecular Biology of the Cell (© Garland Science 2008)
ALTERNATIVE SPLICING
MOLECULAR BIOLOGY – DNA replication, transcription
Figure 6-32a Molecular Biology of the Cell (© Garland Science 2008)
MOLECULAR BIOLOGY – DNA replication, transcription
Figure 6-32b Molecular Biology of the Cell (© Garland Science 2008)
MOLECULAR BIOLOGY – DNA replication, transcription