Reversed Toggle switch+Aptamer-CheZ+lasI-lasR
The part is made up of the standard parts from partsregistry.
This part is composed of improved device in automatically division and quorum sensing parts which will form a negative feedback and helps the forming of the second colony.
This part resulted from the results of experience with part BBa_K557002. More details could be read on the page of BBa_K557002. Given that we expected higher ratios of bacteria moving away, we inserted aptamer-CheZ in the opposite side of the toggle switch.
This part is a translational unit of BBa_K557008 and is constructed of two essential parts in quorum sensing: lasI protein, which produces the chemical signal AI-1, and lasR protein, which accepts chemical signal AI-1. Combined with the lasbox in BBa_K557007, it will form a negative feedback which helps better patterning of the automatically division of bacterial colonies.
RBS (Elowitz 1999) -- defines RBS efficiency
Varies from -6 to +1 region from original sequence to accomodate BioBricks suffix. No secondary structures are formed in the given RBS region. Users should check for secondary structures induced in the RBS by upstream and downstream elements in the +50 to -50 region, as such structures will greatly affect the strength of the RBS. Contact info for this part: Brian Chow
Vinay S Mahajan, Voichita D. Marinescu, Brian Chow, Alexander D Wissner-Gross and Peter Carr IAP, 2003.
autoinducer synthetase for PAI from Pseudomonas aeruginosa (no LVA)
Aptamer-CheZ: theophylline-sensitive synthetic riboswitch+phosphatase which dephosphorylates CheY-P
Escherichia coli, the strain has always been kept in the lab of USTC-IGEM
This part is composed of a theophylline-sensitive aptamer,which will pair the ribosome binding site of the downstream gene in the absence of theophylline and thus inhibit the translation of the gene while expose the ribosome binding site in the presence of theophylline, and the CheZ gene, which is a phosphatase which dephosphorylates CheY-P and causes the flagellum to rotate counterclockwise and is essential for keeping the motility of E.coli. Thus this part provides a ligand-inducible motility and makes it possible to guide E.coli by theophylline.
We found the sequence of this part in literature and tried to design primers to construct it. But we were faced with a challenging problem in primer design, which comes from the basic properties of the aptamer involved. The aptamer tends to pair the ribosome binding site in the absence of theophylline, which is true in PCR, and enables primers to pair to the corresponding parts and the new strand to elongate. We made contact with the author of our reference and found they took different strategies in assembling the aptamer to CheZ instead of PCR. But thanks to the warm help of Professor J. S. Parkinson and Professor J. P. Gallivan, we acquired the sequence of primers used in assembling the aptamer to another gene and designed our own after analyzing them: forward primer:5'-GTTTCGAATTCGCGGCCGCTTCTAGGGTGATACCAGCATCGTCTTGATGCCCTTGGCAGCACCCCGCTGCAAGACAACAAG ATGCAACCATCAATCAAACC-3' reverse primer:5'-GTTTCCTGCAGCGGCCGCTACTAGTATTATTAAAATCCAAGACTATCCAACAAATCGT-3' Besides, we used special protocal of PCR: 96℃ 10min 96℃ 30s, 56℃ 30s, 72℃ 1min for 16 cycles and each cycle the annealing temperature increases by 1℃ 96℃ 30s, 72℃ 30s, 72℃ 1min for 20 cycles 72℃ 10min
Reversed Toggle switch for the convenience of insertion of genes
The part is made by PCR of the part BBa_K228003.
This part is the reverse version of toggle switch so that with the standard prefix and suffix it's more convenient to insert genes on both sides of toggle switch.
lasR activator from P. aeruginosa PAO1(no LVA)
Conversion of the iGEM parts registry to SBOL2.1