This composite part is the union of: *a PoPS in -> cI, lasR out device and *a Plambda-regulated luxR protein generator with Plux downstream. It is a module of the following genetic demultiplexer (demux): {|align="center" | |- | |} where: *PA, PS and PB are three promoters that can be ACTIVATED by the three generic elements A, S and B respectively; *GOI is the ''gene of interest'' that is the output of the system. In particular, '''K081004 is the Selector'''. People who want to use the genetic mux have to assemble: *K081000 under the desired regulation for Channel 0 (for example the generic promoter PA); *K081001 under the desired regulation for Channel 1 (for example the generic promoter PB); *K081002 under the desired regulation for Selector (for example the generic promoter PS); *the desired protein generator downstream of K081000 and K081001 (for example the generic RBS-GOI-T generator);
cI repressor from E. coli phage lambda (+LVA)
Elowitz, M. B. Transport, Assembly, and Dynamics in Systems of Interacting Proteins. Thesis, Princeton Univ., Princeton (1999).
Coding region for the cI repressor based on cI repressor from bacteriophage lambda modified with an LVA tail for rapid degradation of the protein. cI repressor binds to the cI regulator (BBa_R0051).
References (unparsed) here: A synthetic oscillatory network of transcriptional regulators , Elowitz M.B. , Leibler S., Nature(403),335-38: 2000 Octamerization of CI repressor is needed for effective repression of PRM and efficient switching from lysogeny. Ian B. Dodd,1 Alison J. Perkins, Daniel Tsemitsidis, and J. Barry Egan , Genes and Development (Vol 15, No. 22) 3013-3022: 2001 References (unparsed) here: A synthetic oscillatory network of transcriptional regulators , Elowitz M.B. , Leibler S., Nature(403),335-38: 2000 Octamerization of CI repressor is needed for effective repression of PRM and efficient switching from lysogeny. Ian B. Dodd,1 Alison J. Perkins, Daniel Tsemitsidis, and J. Barry Egan , Genes and Development (Vol 15, No. 22) 3013-3022: 2001 BBa_C0051 cI repressor is based on the cI repressor from the Elowitz's repressilator. It has been modified to include a rapid degradation LAA tail, and includes the BioBrick standard assembly head and tail restriction sites. The RBS has been removed. The stop codon has been changed from TAA to a double stop codon TAATAA.
Vinay S Mahajan, Brian Chow, Peter Carr, Voichita Marinescu and Alexander D. Wissner-Gross
A synthetic oscillatory network of transcriptional regulators , Elowitz M.B. , Leibler S., Nature(403),335-38: 2000
The cI regulated promoter is based on the pR promtoer from bacteriohage lambda. The promoter has two two DNA binding sites for lambda cI repressor <bb_part>BBa_C0051</bb_part>. cI binding results in repression of transcription. The specific sequence used here is based on the cI repressible promoter used in the Elowitz repressilator (and references therein).
In order to address concerns about the promoter transcribing in the reverse direction, we have removed the -35 and -10 signals responsible for the promoter activity in the reverse direction. (More details needed here! DE, 2/24/03) Incompatible with host expressing cI repressor.
RBS.1 (strong) -- modified from R. Weiss
Strong RBS based on Ron Weiss thesis. Strength is considered relative to <bb_part>BBa_B0031</bb_part>, <bb_part>BBa_B0032</bb_part>, <bb_part>BBa_B0033</bb_part>.
Varies from -6 to +1 region from original sequence to accomodate BioBricks suffix ("orig" in figure 4-14 of Ron Weiss thesis). 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 Brian Chow
Vinay S Mahajan, Voichita D. Marinescu, Brian Chow, Alexander D Wissner-Gross and Peter Carr IAP, 2003.
V. fischeri <genbank>AF170104</genbank>
In complex with HSL, LuxR binds to the Lux promoter, activating transcription from Pr <bb_part>BBa_R0062</bb_part>, and repressing transcription from Pl <bb_part>BBa_R0063</bb_part>. The lux cassette of V. fischeri contains a left and a right promoter. The right promoter gives weak constitutive expression of downstream genes.This expression is up-regulated by the action of the Lux activator, LuxR complexed to HSL. Two molecules of LuxR protein form a complex with two molecules the signalling compound homoserine lactone (HSL). This complex binds to a palindromic site on the promoter, increasing the rate of transcription.
2 silent point mutants were introduced in the coding sequence to remove internal XbaI and PstI sites. Mutation sites were chosen to replace codons commonly used in E. coli with codons used at a similar frequency.
Vinay S Mahajan, Voichita D. Marinescu, Brian Chow, Alexander D Wissner-Gross and Peter Carr
Promoter (luxR & HSL regulated -- lux pR)
Promoter activated by LuxR in concert with HSL The lux cassette of V. fischeri contains a left and a right promoter. The right promoter gives weak constitutive expression of downstream genes.This expression is up-regulated by the action of the LuxR activator protein complexed with the autoinducer, 3-oxo-hexanoyl-HSL. Two molecules of LuxR protein form a complex with two molecules of the signalling compound homoserine lactone (HSL). This complex binds to a palindromic site on the promoter, increasing the rate of transcription.
This promoter is based on the Vibrio fischeri quorum sensing gene promoters. Two genes LuxI and LuxR and transcribed in opposite directions as shown below. The original sequence from which the parts <bb_part>BBa_R0062</bb_part> and <bb_part>BBa_R0063</bb_part> were derived is shown in the picture below. <img src="<bb_file>Image1.gif</bb_file>" width="614" height="362">
lasR activator from P. aeruginosa PAO1(+LVA)
Genbank: NC_002516 (www.ncbi.nlm.nih.gov)
coding region for lasR protein, which accepts chemical signal AI-1 (made by lasI protein)
Mutated 480 from g to a to remove PstI site
modified E. coli thr terminator, replaced all A-T pairs in stem with C-G pairs
Artificial terminator, estimated %T~>90% *8bp stem, 6nt loop *Bidirectional, estimated reverse %T~>90%
Bidirectional, with the reverse estimated to be less effective than the forward. Has a polyA tail of 9 residues.
Conversion of the iGEM parts registry to SBOL2.1