Part:BBa_K2036001

CIII

Inhibitor of Ftsh( ATP-dependent host metalloprotease).

The CIII protein encoded by the temperate coliphage lambda acts as an inhibitor of the ubiquitous Escherichia coli metalloprotease HflB (FtsH). This inhibition results in the stabilization of transcription factor lambda CII, thereby helping the phage to lysogenize the host bacterium.Lambda CIII also protects sigma(32), another specific substrate of HflB.
It have been recently shown that the protection of CII from HflB by CIII involves direct CIII-HflB binding, without any interaction between CII and CIII. Such a mode of action for lambda CIII would be independent of the HflB substrate. In this study, we tested the ability of CIII to protect sigma(32) from HflB digestion. The inhibition of HflB-mediated proteolysis of sigma(32) by CIII is very similar to that of lambda CII, characterized by an enhanced protection by the core CIII peptide CIII (amino acids 14-41 of lambda CIII) and a lack of interaction between sigma(32) and CIII.

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]

Protein&protein reaction

We had submitted and documented RBS-CIII-RBS-CIII-RBS-CII-TT-pRE-RBS-GFP-LVAssrAtag (BBa_K2036014) and RBS-CII-RBS-CII-RBS-CII-TT-pRE-RBS-GFP-LVAssrAtag (BBa_K2036015). These two parts were to test whether CIII can protect CII from being degraded by Ftsh by competitive inhibition.

Fig1: According to the flourescence measurement curve above, we can see clearly that GFP level of CIII test circuit increasedover time and it showed significant difference from two control groups. It indicates that tandemly expressed CIII can efficiently protect CII from being degraded by Ftsh.