Part:BBa_K2992014

5-UTR containing RBS for botR gene from C. botulinum

5’-UTR containing RBS region for botR gene in C. botulinum

Usage and Biology

The native 5’-UTR containing the RBS is found naturally upstream of botR in C. botulinum. BotR is an alternative sigma factor involved in the positive regulation of botulinum neurotoxin and associated genes. In our project, we use PbotR to drive the expression of botR (BBa_K2992002) which in turn, regulates the production of our reporter genes which we have placed under the control of a BotR-activated promoter (BBa_K2992028, BBa_K2992029, BBa_K2992030, BBa_K2992034, BBa_K2992035, BBa_K2992036). Doing so allowed us to link BotR expression with the trasncriptional activation of our reporter genes.

Characterisation

This basic part was used for the assembly of our composite parts and characterised using FAST, GusA and acetone assays. More information can be found on our Results Page.





Characterisation of PbotR (comprising parts BBa_K2992012 and https://parts.igem.org/Part:BBa_K2992014 BBa_K2992014) against Pfdx, Pthl and Pntnh using the FAST fluorescent assay, showed PbotR to be a relatively weak promoter in both E.coli and C.sporogenes.

The data demonstrated appreciable acetone production of >2nM concentration when using either the native PbotR promoter and associated 5’-UTR+RBS or the RBS only construct to permit polar transcription from PpyrKDE. Considerable acetone production (4-6nM) was observed when using the constitutive clostridial promoter Pfdx. Crucially, acetone production was comparably scant when botR was absent from the genome of C. sporogenes and when no promoter was used to drive expression of the acetone production operon. These data provide experimental validation for the production of acetone in C. sporogenes as a model for Botulinum toxin prediction in foodstuffs.

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]

References

Raffestin, S., Dupuy, B., Marvaud, J. and Popoff, M. (2004). BotR/A and TetR are alternative RNA polymerase sigma factors controlling the expression of the neurotoxin and associated protein genes in Clostridium botulinum type A and Clostridium tetani. Molecular Microbiology, 55(1), pp.235-249.

Zhang, Z., Korkeala, H., Dahlsten, E., Sahala, E., Heap, J., Minton, N. and Lindström, M. (2013). Two-Component Signal Transduction System CBO0787/CBO0786 Represses Transcription from Botulinum Neurotoxin Promoters in Clostridium botulinum ATCC 3502. PLoS Pathogens, 9(3), p.e1003252.