Engineering E.Coli to see Light

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Engineering E.Coli to see Light

• Voigt CA et. al. 2005

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Light Engineering Imaging using E.Coli
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System
Sensor
Signal Transducer
Effector
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Stimulus

• Red Light
• Highly defined edges
• Two-dimensional image

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Sensor

• Phytochrome
• Membrane bound extracellular sensor
• Intracellular regulator
• Fusion protein phytochrome and EnvZ histidine
  kinase domain

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Photoreceptor Expression

• PCB not produced in E.Coli
• Introduction of PCB synthesis genes
• Converts haem into PCB

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Transduction Mechanism

• Red light represses EnvZ auto-phosphorylation

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Output

• OmpR-P activates promoter linked to reporter gene
• lacZ reporter produce black compound

OmpR-P dependent ompC promoter
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System Revisited
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Review

• Created novel genetic circuit
• High definition film
• (100 megapixels per square inch)
• lacZ expression as a function of light intensity
  / wavelength
• Transfer function

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Light Canon
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Characterisation

• Macro
• Resolution
• Micro
• Transfer function
• SigB activity as a function of
• Intensity
• Wavelength