Lecture 7
? 8.1 Major Modes of Regulation
? 8.2 Inhibiting Enzyme Activity
? 8.3 Modification of Enzymes
? 8.4 DNA Binding Proteins
? 8.5 Negative Control of Transcription,
Repression and Induction
? 8.6 Positive Control of Transcription
Regulation
? different conditions require different strategies
– changes in nutrients available
– sporulation
? impractical to make every protein
? excess proteins may be detrimental
? allows specific response
? activities can be regulated at multiple levels
Figure 8.1
Different Regulatory Mechanisms
Figure 8.2
Feedback Inhibition
Figure 8.3
Allosteric Effector
Figure 8.4
Feedback Inhibition,Branched
Biosynthetic Pathway
Figure 8.5
Feedback Inhibition of a
Common Pathway
Enzyme Modifications
? covalent modification changes protein
conformation
– addition of AMP,ADP
– phosphorylation
– methylation
Figure 8.6
Adenylation of Glutamine Synthetase
Figure 8.10
Repression of Enzyme Activity
Figure 8.11
Induction of Enzyme Activity
Figure 8.12
Enzyme Repression
Enzyme Induction
Figure 8.13
Positive Control of Enzyme
Induction
Figure 8.14
Interaction of Activator Protein
with RNA Polymerase
Figure 8.16
Figure 8.7
Figure 8.8
Lambda repressor