Part:BBa_K1017602

37℃ RBS + mGFP

This biobrick is comprised of 37 degrees Celsius RBS and mGFP. 37℃ RBS, a RBS which on/off is controlled by temperature. mGFP is a green fluorescent protein. In our project, we use this part to conduct the test of temperature regulated-system. P_cons promoter is a constitutive promoter. This promoter can be used to tune the expression level of constitutively expressed parts. By adding a P_cons promoter and controlling temperature , we can measure the O.D. value to determine the level of GFP's expression.

Mechanism

Unlike normal RBS, the 37℃ RBS has a unique rather stable hairpin structure which shape like a lock. If the temperature drops below 37℃, the base-pairing neucleotides on the RNA will form a stable hairpin structure, occluding the Shine-Dalgarno sequence thus disabling the ribosome to bind. The base-pairing of this RNA region will block the expression of the protein encoded within.When the temperature is higher than 37℃, the bonds will be broken, the hairpin would be unfolded, causing the Shine-Dalgarno sequence to be exposed and permitting the binding of the ribosome, which then starts the translational machinery so the downstream gene, mGFP, can be expressed.

Data

From chart 1, we can clearly found that the time to reach same O.D. value(0.8) various as the temperature changes. The expression of mGFP under 37°C and 42°C reached a higher OD value in less time than the expression below 37°C. This demonstrates the fact that 37°C RBS functions more efficiently above or at 37°C. On the other hand, the fact that 37°C RBS leads to moderate expression even under 37°C degree might be a problem, since then we cannot make sure that only single gene is expressed under 37°C.

Sequence and Features

Assembly Compatibility:

• 10
  COMPATIBLE WITH RFC[10]
• 12
  COMPATIBLE WITH RFC[12]
• 21
  COMPATIBLE WITH RFC[21]
• 23
  COMPATIBLE WITH RFC[23]
• 25
  COMPATIBLE WITH RFC[25]
• 1000
  COMPATIBLE WITH RFC[1000]