1. Regulatory RNAs riboswitch RNA Regulation by RNAs in Bacteria
Chapter 20 Opener
Regulatory RNAs
riboswitch RNA
Regulation by RNAs in Bacteria
6S RNA of E. coli down regulates transcription from many sigma 70 promoters at high level in stationary phase. In this phase, sigma s transcribes genes by sigma s promoters.
Chapter 20 Opener
Regulatory RNAs
Regulation by RNAs in Bacteria
6S RNA of E. coli down regulates transcription from many sigma 70 promoters at high level in stationary phase. In this phase, sigma s transcribes genes by sigma s promoters.

2. Figure 20-1
Activation and repression of translation by(depending on) sRNAs (small bacterial regulatory RNAs)
Figure 20-1
Activation and repression of translation by sRNAs 2

3. Organization of riboswitch RNAs (varies with
Figure 20-2
Organization of riboswitch RNAs (varies with
nucleotides) in primary RNA
Figure 20-2
Organization of riboswitch RNAs
riboswitch RNAs: aptamer and expression platform 3

4. S-Adenosyl methionine (SAM) riboswitch
Figure 20-3
Riboswitches regulate transcription termination or translation initiation
Figure 20-3
Riboswitches regulate transcription termination or translation initiation
S-Adenosyl methionine (SAM) riboswitch 4

5. Changes in secondary structure of a SAM riboswitch
Figure 20-4
Changes in secondary structure of a SAM riboswitch
Figure 20-4
©2003 Macmillan
Changes in secondary structure of a SAM riboswitch 5

6. Riboswitchs respond to a ranges of metabolites
Figure 20-5
Riboswitchs respond to a ranges of metabolites
Figure 20-5
Riboswitchs respond to a ranges of metabolites 6

7. trp operon Box 20-1-1 Box 20-1-1 trp operon Anthaanillate synthase :
chorismate + L-glutamine ------ anthranilate + pyruvate + L-glutamate (involved in also
trptophan synthase) 7

8. Box
Box 8

9. Other trp genes transcribed.
Box
Other trp genes transcribed.
Box
Other genes transcribed. 9

10. Organization of the CRISPR locus
Figure 20-6
Organization of the CRISPR locus
Figure 20-6
©2010 Elsevier
Organization of the CRISPR locus
CRISPRs (clustered regularly interspaced short palindromic repeats) 10

11. Core genes in red (cas3 etc.)
Figure 20-7
Core genes in red (cas3 etc.)
Streptococcus
Pyrococcus
Figure 20-7
©2010 Elsevier
Streptococcus
Pyrococcus
Core genes in red 11

12. Proto-spacers (sequencers) are acquired from infecting viruses.
Figure 20-8
Proto-spacers (sequencers) are acquired from infecting viruses.
Figure 20-8
©2010 Elsevier
Prot(최초의)-spacers (sequencers) are acquired from infecting viruses. 12

13. Figure 20-9a
A CRISPR is transcribed as a single long RNA, which is then processed into shorter RNA species that target destruction of invading DNA or RNA
In here targets DNA
(In E. coli)
Figure 20-9a
A CRISPR is transcribed as a single long RNA, which is then processed into shorter RNA species that target destruction of invading DNA or RNA 13

14. a single long RNA, which is then processed into shorter RNA species
Figure 20-9b
a single long RNA, which is then processed into shorter RNA species
In P. furiosus, targets RNA
Figure 20-9b 14

15. Regulatory RNAs are widespread in eukaryotes.

16. Regulatory RNAs are widespread in eukaryotes.
Figure 20-10
Regulatory RNAs are widespread in eukaryotes.
si(small interfering) RNAs
are from dsRNA.
mi(micro) RNAs are from
precursor RNAs.
piwi-interacting RNAs are
expressed usually in
germline.
Figure 20-10
si(small interfering) RNA
RISC(RNA induced silencing complex)
RISC(RNA induced silencing complex) 16

17. RNA dependent RNA polymerase (RdRP)
Figure 20-11
Small RNA must be denatured to give guide RNA – the strand that gives RISC specificity and passenger RNA that usually get discarded.
Figure 20-11
Small RNA must be denatured to give guide RNA – the strand that gives RISC specificity and passenger RNA that usually get discarded.
RNA dependent RNA polymerase (RdRP)
RNA dependent RNA polymerase (RdRP) 17

18. Synthesis and function of miRNA molecules

19. miRNA has structure that assist in identifying and their target genes
Figure 20-12
Arms of stem loop
miRNA has structure that assist in identifying and their target genes
Figure 20-12
Arms of stem loop
Has structure that assist in identifying and their target genes 19

20. miRNAs are coded in both introns and exons in RNA
Figure 20-13
miRNAs are coded in both introns and exons in RNA
Figure 20-13
miRNAs are coded in both introns and exons in RNA 20

21. Figure 20-14
Figure 20-14 21

22. Active miRNA is generated through a two step nucleolytic processing
Figure 20-15
Primary miRNA
Active miRNA is generated through a two step nucleolytic processing
RNAase III family enzyme cleaves into pre-miRNA and leaves a 2 nucleotide overhange that is important for recognition of that RNA by next enzyme
Microprocessor complex
Figure 20-15
Active miRNA is generated through a two step nucleolytic processing
Microprocessor complex
RNAase III family enzyme cleaves into pre-miRNA and leaves a 2 nucleotide overhange that is important for recognition of that RNA by next enzyme 22

23. protein RNA RNAase III site and PAZ domain. Dicer also has APTase.
Figure 20-16
protein
RNAase III site and PAZ domain. Dicer also has APTase.
Figure 20-16
RNAase III site and PAZ domain. Dicer also has APTase. protein
RNA 23

24. Figure 20-17
Crystal structure of Argonaute that is central component of RISC(RNA inducing silencing complex)
Figure 20-17
Crystal structure of Argonaute that is central component of RISC 24

25. Silencing gene expression by small RNAs:
Figure 20-17b
Silencing gene expression by small RNAs:
Incorporation of a guide strand RNA(active form of regulatory RNA: gRNA) into RISC makes the mature complex that is ready to silence gene expression
Figure 20-17b
©2004 AAAS
Silencing gene expression by small RNAs: Incorporation of a guide strand RNA into RISC makes the mature complex that is ready to silence gene expression 25

26. Model for RITS recruitment and silencing of centromeres (in S. pombe)
Figure 20-18
Small RNAs can transcriptionally silence genes by directing chromatin modification
RNA dependent RNA polymerase
Model for RITS recruitment and silencing of centromeres (in S. pombe)
Figure 20-18
Small RNAs can transcriptionally silence genes by directing chromatin modification
Model for RITS recruitment and silencing of centromeres 26

27. Bacterial CRISPR defense system: acquire spacers frominfecting phage)
Figure 20-19
Bacterial CRISPR defense system: acquire spacers frominfecting phage)
Animal piRNA defense system:
Transposon sequence arrives passively within the piRNA cluster
Figure 20-19
©2010 Elsevier
Bacterial CRISPR
Animal piRNA defense system 27

28. Figure 20-20
RNA interference can be induced in worms by feeding bacteria expressing dsRNA
Figure 20-20
RNA interference can be induced in worms by feeding bacteria expressing dsRNA 28

29. Long non-coding RNAs (Inc RNAs) and X-inactivation
Figure 20-21
Long non-coding RNAs (Inc RNAs) and X-inactivation
Inc RNAs have many roles in gene regulation, including cis and trans effect on transcription
X-inactivation create mosaic individuals (in calico cat)
Xist is Inc RNAs that inactivate a single chromosome in female mammal.
Figure 20-21
Long non-coding RNAs and X-inactivation 29

30. Figure 20-22
Figure 20-22 30

31. Figure 20-23
Figure 20-23 31