Part:BBa_K3425021

iGEM Type IIS standard Level 1 Dummy (TU-DY)

Type IIS iGEM standard allows for fast and efficient construction of transcriptional units (TU) and multi-transcriptional units (MTU) in groups of four components. These components are needed in Level 1 assemblies (promoter, RBS, CDS and terminator) but might not be needed in higher level assemblies if the amount of transcriptional units in your system is not a multiple of four.

For this reason, placeholders called dummy parts were created based on an existing Modular Assembly method [1]. These parts mimic a basic Type IIS part or a transcriptional unit and can be included in the assembly whenever needed.

This page corresponds to TU-DY which was cloned to all pOdd plasmids (pSB1K0#) and mimics transcriptional units. Not present in the part would be BsaI recognition sites, which are positioned so the fusion sites are cut in the proper way. The part with these sites can be found in Team Uppsala 2020's Parts page.

More information about this cloning standard and dummy parts can be found in Team Uppsala 2020's iGEM Type IIS standard guidebook

Usage and Biology

Experiments with cloning all TU-DY together in pSB3C11 showed that most clones contain deletions or insertions of various sizes in the area of the "multi-dummy" sequence.

This is probably due to the short and repetitive sequence generated by the dummies, since all of them contain the same fusion sites and spacer in between. More information can be found in the composite part BBa_K3425064.

Dummy parts are only supposed to be fillers that allow the cloning reaction to ligate properly when you have less than four parts to assemble. In this sense, this dummy sequence works as intended. However, it is not ideal to have unpredictable mutations occurring systematically. Longer dummy parts which are all different were designed in silico as a better alternative.

The following table details the part numbers and names of these new dummies (which contains the plasmid they should be cloned into), along with the transcriptional unit they are mimicking.

Registry Number	Name	Mimics
BBa_K3425023	pSB1K01-DY	TU1
BBa_K3425024	pSB1K02-DY	TU2
BBa_K3425025	pSB1K03-DY	TU3
BBa_K3425026	pSB1K04-DY	TU4

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

1. Binder, A., Lambert, J., Morbitzer, R., Popp, C., Ott, T., Lahaye, T., and Parniske, M. (2014) A Modular Plasmid Assembly Kit for Multigene Expression, Gene Silencing and Silencing Rescue in Plants. PLOS ONE. 9, e88218