CHAPTER 10 Regulation of Gene Expression in Bacteria and Their Viruses CHAPTER 10 Regulation of Gene Expression in Bacteria and Their Viruses Copyright.

CHAPTER 10

Regulation of Gene Expression in Bacteria and Their Viruses

CHAPTER 10

Regulation of Gene Expression in Bacteria and Their Viruses

Copyright 2008 © W H Freeman and Company

CHAPTER OUTLINE10.1 Gene regulation

10.2 Discovery of the lac system: negative control

10.3 Catabolite repression of the lac operon: positive control

10.4 Dual positive and negative control: the arabinose operon

10.5 Metabolic pathways and additional levels of regulation: attenuation

10.6 Bacteriophage life cycles: more regulators, complex operons

10.7 Alternative sigma factors regulate large sets of genes

Regulatory proteins control transcription

Figure 10-2

Allosteric effectors bind to regulatory proteins

Figure 10-3

Repressor protein controls the lac operon

Figure 10-4

Lactose is broken down into two sugars

Figure 10-5

The lac operon is transcribed only in the presence of lactose

Figure 10-6a

The lac operon is transcribed only in the presence of lactose

Figure 10-6b

Structure of IPTG

Figure 10-7

Table 10-1

Operators are cis-acting

Figure 10-8

Table 10-2

Repressors are trans-acting

Figure 10-9

Table 10-3

The repressor contains a lactose-binding site

Figure 10-10

RNA polymerase contacts the promoter at specific sequences

Figure 10-11

The operator is a specific DNA sequence

Figure 10-12

Glucose levels control the lac operon

Figure 10-13

Glucose levels control the lac operon

Figure 10-13a

Glucose levels control the lac operon

Figure 10-13b

Many DNA binding sites are symmetrical

Figure 10-14

Binding of CAP bends DNA

Figure 10-15

CAP and RNA polymerase bind next to each other

Figure 10-16

Negative and positive control of the lac operon

Figure 10-17

Negative and positive control of the lac operon

Figure 10-17a

Negative and positive control of the lac operon

Figure 10-17b

Negative and positive control of the lac operon

Figure 10-17c

Repression and activation compared

Figure 10-18

Repression and activation compared

Figure 10-18a

Repression and activation compared

Figure 10-18b

Map of the ara operon

Figure 10-19

AraC serves as an activator and as a repressor

Figure 10-20

Gene order in the trp operon corresponds to reaction order in

the biosynthetic pathway

Figure 10-21

The trp mRNA leader sequence contains an attenuator region

and two tryptophan codons

Figure 10-22

Abundant tryptophan attenuates transcription of the trp operon

Figure 10-23

Leader peptides of amino acid biosynthesis operons

Figure 10-24

The life cycle of bacteriophage

Figure 10-25

Phage genome is organized for coordinate control

Figure 10-26

Figure 10-27

The lysogenic-versus-lytic cycle is determined by repressoroccupancy on the OR operators

Helix-turn-helix is a common DNA-binding motif

Figure 10-28

Amino acid side chains determine the specificity of DNA binding

Figure 10-29

factors control clusters of unlinked genes

Figure 10-30a

factors control clusters of unlinked genes

Figure 10-30b