Prokaryotic Gene Regulation April 22, 2015 Richard D. Howells, PhD MSB E-643

Slides:



Advertisements
Similar presentations
The need for gene regulation Bacterial genome4,000 genes Human genome100,000 genes Not all expressed at any one time May need very high levels e.g. translation.
Advertisements

Control of Gene Expression
Gene Expression in Prokaryotes. Why regulate gene expression? It takes a lot of energy to make RNA and protein. It takes a lot of energy to make RNA and.
Ch 18 Gene Regulation. Consider: A multicellular organism (Pliny) Do each of his cells have the same genes? Yes, with an exception: germ cells are haploid.
Genetic Regulatory Mechanisms. Control of Gene Expression Transcriptional control Clustering of genes with related function Coordinate control of genes.
The lac operon – An inducible operon Genes are either cis (coupling) acting –Genes affect those adjacent to themselves –Operator and structural genes Or.
Summary: When and where do cells have control over which genes are expressed and which proteins are active? Proteins are activated through processing.
Gene regulation. Gene expression models  Prokaryotes and Eukaryotes employ common and different methods of gene regulation  Prokaryotic models 1. Trp.
Transcription Regulation The Lac Operon – a paradigm for all transcription regulation.
Regulation of prokaryotic transcription 1.Single-celled organisms with short doubling times must respond extremely rapidly to their environment. 2.Half-life.
The lac Operon of E. Coli AMATH 882 Lecture 8, Feb. 7, 2011.
The Lac Operon Regulation of Prokaryotic Genes. n Scientists investigated a transcriptionally regulation system using the lactose metabolism system in.
Genetic Regulatory Mechanisms
Enzyme Regulation. Constitutive enzymes –Enzymes needed at the same level all of the time Regulated enzymes –Enzymes needed under some conditions but.
Control of Gene Expression in Prokaryotes
Chapter 11 Molecular Mechanisms of Gene regulation Jones and Bartlett Publishers © 2005.
Gene Regulation Prokaryotes (no nucleus). Lac operon System of genes that can turn on and off in E. coli (bacteria). These genes make enzymes that break.
How to bioengineer a novel system? Obtain a sequence by PCR, then clone it into a suitable plasmid We’re adding DNA, but want E. coli to make a protein!
The lac operon of the Escherichia coli bacterium - Positive transcriptional control of the lac operon by the polymerase transactivator protein cAMP-CAP.
Announcements 1. Reading Ch. 15: skim btm Look over problems Ch. 15: 5, 6, 7.
To understand the concept of the gene function control. To understand the concept of the gene function control. To describe the operon model of prokaryotic.
Negative regulatory proteins bind to operator sequences in the DNA and prevent or weaken RNA polymerase binding.
Control of Prokaryotic Gene Expression. Prokaryotic Regulation of Genes Regulating Biochemical Pathway for Tryptophan Synthesis. 1.Produce something that.
A. Structure of RNA B. Major Classes of RNA C. Transcription in Prokaryotes D. Transcription in Eukaryotes E. Post-transcriptional Processing of Eukaryotic.
Regulation of transcription in prokaryotes
Regulation of gene expression References: 1.Stryer: “Biochemistry”, 5 th Ed. 2.Hames & Hooper: “Instant Notes in Biochemistry”, 2 nd Ed.
Operons. Big picture Prokaryotic control of genome expression Prokaryotic control of genome expression 2 levels of control 2 levels of control  Change.
Bacterial Operons A model of gene expression regulation Ch 18.4.
Regulation of gene and cellular activity
Promoter sequences from 10 bacteriophage and bacterial genes
Differential Expression of Genes  Prokaryotes and eukaryotes precisely regulate gene expression in response to environmental conditions  In multicellular.
GENE REGULATION. Virtually every cell in your body contains a complete set of genes Virtually every cell in your body contains a complete set of genes.
Chapter 13. Regulation of gene expression References: 1.Stryer: “Biochemistry”, 5 th Ed. 2.Hames & Hooper: “Instant Notes in Biochemistry”, 2 nd Ed.
Prokaryotic Regulation Regulation of Gene Expression – Part I Spring Althoff Reference: Mader & Windelspecht Ch. 13) Lec 18.
Translation mRNA exits the nucleus through the nuclear pores In the cytoplasm, it joins with the other key players to assemble a polypeptide. The other.
Genetica per Scienze Naturali a.a prof S. Presciuttini 1. The logic of prokaryotic transcriptional regulation In addition to the sigma factors that.
Bacterial Gene Expression and Regulation
Gene Regulation Gene Regulation in Prokaryotes – the Jacob-Monad Model Gene Regulation in Prokaryotes – the Jacob-Monad Model certain genes are transcribed.
Gene Regulation, Part 1 Lecture 15 Fall Metabolic Control in Bacteria Regulate enzymes already present –Feedback Inhibition –Fast response Control.
©2000 Timothy G. Standish Ecclesiastes 3:1 1To every thing there is a season, and a time to every purpose under the heaven:
FIGURE 6.1. RNA contains the sugar ribose and the base uracil in place of deoxyribose and thymine.
Complexities of Gene Expression Cells have regulated, complex systems –Not all genes are expressed in every cell –Many genes are not expressed all of.
Control, Genomes and Environment Cellular Control – The lac operon.
Control of Transcription DNA has “on” and “off” switches Activator –protein that binds near gene’s promoter region - allows RNA polymerase to transcribe.
Active from 3:20 today thru midnight on November 25 Homework.
Gene regulation.
Control of Gene Expression in Prokaryotes
Operons In E. coli, all 5 genes that code for the production of the enzymes that make tryptophan (when necessary) are all located together Benefit: A single.
The Lac Operon An inducible operon
Control of Gene Expression
Lac Operon Lactose is a disaccharide used an energy source for bacteria when glucose is not available in environment Catabolism of lactose only takes place.
Goals today: Describe the parts of an operon
The lac Operon of E. Coli AMATH 882 Lecture 11, Feb. 12, 2013
Regulation of gene and cellular activity
Gene Regulation.
Transcriptional Regulation
Lac Operon.
Controlling Gene Expression
Chapter 12.5 Gene Regulation.
Regulation of Gene Expression
Prokaryotic Gene Regulation
Agenda 3/16 Genes Expression Warm Up Prokaryotic Control Lecture
Regulation of Gene Expression
Lecture 12 RNA polymerase as a molecular motor Transcriptional control.
Gene Regulation Packet #22.
Control of Prokaryotic (Bacterial) Genes Different from Eukaryotes!
Gene Regulation certain genes are transcribed all the time – constitutive genes synthesis of some proteins is regulated and are produced only when needed.
Transcriptional Regulation in Prokaryotes.
Objective 3: TSWBAT recognize the processes by which bacteria respond to environmental changes by regulating transcription.
Prokaryotic (Bacterial) Gene Regulation
Presentation transcript:

Prokaryotic Gene Regulation April 22, 2015 Richard D. Howells, PhD MSB E-643

Objectives During this presentation, you may  catch up on needed sleep  recall the process of transcription  appreciate how the lac and trp operons are regulated in bacteria Lecture 132

3 General structure of the tandem arrays of pre-rRNA transcription units

44 RNA is synthesized 5’ to 3’ based on the DNA sequence of the template DNA strand

5 The bacterial RNA polymerase

6 Bacterial RNA Polymerase

7 Inactivation of the prokaryotic RNA polymerase by rifampin - a drug used for treatment of tuberculosis

8 Prokaryotic promoter region: landmark for site of transcription initiation

9 The Lactose (Lac) Operon of Escherichia coli Lac I encodes lac repressor Lac Z encodes  -galactosidase Lac Y encodes lac permease Lac A encodes  -galactoside transacetylase

10 Lactose metabolism in E. coli

11 Transcriptional Regulation of the Lac Operon

18 The Lac Operon Promoter

The lac promoter vs. the promoter consensus sequence 13

14 Structure of cAMP

15 Control of the lac operon by glucose and cAMP

cAMP-CAP (CRP) homodimer (yellow domain interacts with RNA pol) 16

tTThe T 17 The cAMP-CAP complex activates transcription of the lac operon

18 Lac Operon Regulation

Regulation of the trp operon in E. coli 19

Trp repressor homodimer bound to Trp and the trp operator 20

21 Rho-independent termination of transcription

Transcriptional attenuation in the trp operon 22

Transcriptional attenuation in the trp operon 23

Transcriptional attenuation in the trp operon 24

Attenuation in the trp operon 25 (does not cause attenuation)

Leader sequences of other AA operons in E. coli subject to attenuation 26

Feedback: Privacy Policy Feedback
Do Not Sell My Personal Information
About project: SlidePlayer Terms of Service

© 2024 SlidePlayer.com Inc. All rights reserved.