Part:BBa_K525121

S-layer cspB from Corynebacterium glutamicum with TAT-Sequence and lipid anchor, PT7 and RBS

Usage and Biology

S-layer proteins can be used as scaffold for nanobiotechnological applications and devices by e.g. fusing the S-layer's self-assembly domain to other functional protein domains. It is possible to coat surfaces and liposomes with S-layers. A big advantage of S-layers: after expressing in E. coli and purification, the nanobiotechnological system is cell-free. This enhances the biological security of a device.

This fluorescent S-layer fusion protein is used to characterize purification methods and the S-layer's ability to self-assemble on surfaces.

Important parameters

Experiment	Characteristic	Result
Expression (E. coli)	Localisation	cell membrane
	Compatibility	E. coli KRX
	Inductor for expression	L-rhamnose for induction of T7 polymerase
Characteristics	Molecular weight
	Theoretical pI

Sequence and Features

Assembly Compatibility:

• 10
  COMPATIBLE WITH RFC[10]
• 12
  COMPATIBLE WITH RFC[12]
• 21
  INCOMPATIBLE WITH RFC[21]

  Illegal BamHI site found at 1421
  Illegal XhoI site found at 248
  Illegal XhoI site found at 866
  
• 23
  COMPATIBLE WITH RFC[23]
• 25
  COMPATIBLE WITH RFC[25]
• 1000
  INCOMPATIBLE WITH RFC[1000]

  Illegal BsaI.rc site found at 1400
  Illegal SapI site found at 647
  Illegal SapI site found at 859
  Illegal SapI site found at 1407
  

Expression in E. coli

The CspB gen was fused with a monomeric RFP (BBa_E1010) using [http://2011.igem.org/Team:Bielefeld-Germany/Protocols#Gibson_assembly Gibson assembly] for characterization.

The CspB|mRFP fusion protein was overexpressed in E. coli KRX after induction of T7 polymerase by supplementation of 0,1 % L-rhamnose using the [http://2011.igem.org/Team:Bielefeld-Germany/Protocols/Downstream-processing#Expression_of_S-layer_genes_in_E._coli autinduction protocol] from promega.

Figure 1: Growthcurve of E. coli KRX expressing the fusion protein of CspB and mRFP with and without induction. A curve depicting KRX wildtype is shown for comparsion.

Figure 2: RFU to OD₆₀₀ ratio of E. coli KRX expressing the fusion protein of CspB and mRFP with and without induction. A curve depicting KRX wildtype is shown for comparsion.