1

Synthetic Biology Part 1:

Introduction

Input

Output

AND

Gene A

Gene B

Gene C

micro.magnet.fsu.edu

Prokaryotic cell

3

Cell-Cell communication in prokaryotes

http://parts.mit.edu/igem07/index.php/Chiba/Communication

4

DNA

RNA

PROTEIN

Transcription byRNA polymerase

Translation byribosomes

Flow of genetic information

5

DNA structure

6

Gene structure

Gene Gene

Promoter Coding sequence Terminator

chromosome

7

RNA

Transcription start site

Promoter

Gene structure

Terminator

8

Promoter structure

9bioap.wikispaces.com

Transcription

10

Transcription

11

Transcription

12

AUG UGA

Ribosome binding siteto initiate translation

Start codon(first amino acid of the protein)

Stop codon(signal to end

protein synthesis)

= untranslated region

5’ 3’

mRNA structure

13

+1

-10Box

TATAA

-35Box

TTGTCA RNA

Core promoter = Binding site for RNA polymerase

In this configuration transcription is ON

RNA Pol

Transcription

14

RNA

+1

RNA PolA

A = Activator of transcription

bad promoter

Transcription

15

+1

-10box

-35box

operator

R

R = Repressor

In this configuration RNA Polymerase cannot bindtranscription is OFF

X

Repression of transcription

16

• The lactose operon of E. coli

R

lacIrepressor R

-35 O -10

Transcription is OFF

Active repressor

X

Repression of transcription

17

• The lactose operon of E. coli

R

lacIrepressor

-35 O -10

Transcription is ON

Inactiverepressor = inducer (lactose)

RNA Pol

X

Induction of gene expression

18

AUG UGA5’ 3’

3’ 5’

siRNA

Binding of siRNA causes mRNA degradation

TranslationX

Silencing by antisense RNA

19

AUG UGA5’ 3’

Ribozymes+ aptamer

RNA cleavage

Repression by mRNA cleavage

20

AUG UGA

Ribosome binding siteto initiate translation

Start codon(first amino acid of the protein)

Stop codon(signal to end

protein synthesis)

= untranslated region

5’ 3’

mRNA structure

21

Translation

22

brooklyn.cuny.edu

The genetic code

23

Protein structure

biochem.arizona.edu