A hybrid promoter controls the production of LuxR and ccdB. The promoter is activated by HSL-LuxR complex and repressed by P22 c2. The LuxR coding region is preceded by a strong RBS and followed by a bad terminator (60% efficiency). This means there is read through into the ccdB coding region which can be translated from a very weak RBS. If the P22 c2 repressor is absent, there should be a strong enough LuxR background to allow autoactivation if HSL is added. The amound of ccdB should be sublethal as long as there is no significant activation.
The ratio of fully activated transcription to background transcription is the sole determinant of the ratio of ccdB produced in the activated state to the background state. Modeling has shown that this should be ok.
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.
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
Double terminator consisting of BBa_B0010 and BBa_B0012
Double terminator consisting of BBa_B0012 and BBa_B0011
RBS.4 (weaker) -- derivative of BBa_0030
Weaker RBS based on Ron Weiss thesis. Strengths relative to <bb_part>BBa_B0030</bb_part>, <bb_part>BBa_B0031</bb_part>, <bb_part>BBa_B0032</bb_part>.
Varies from -6 to +1 region from original sequence to accomodate BioBricks suffix ("RBS-3" in figure 4-14 of 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 for this part: Brian Chow
Hybrid promoter: HSL-LuxR activated, P22 C2 repressed
Hybrid promoter consisting of the Lux box which overlaps partly with -35 box. Binding sites for P22 C2 OR2 and OR1 are located between the -35 and -10 boxes and downstream of them respectively.
-35 box is partly composite. -10 is taken from the P22 phage PR regulatory region
Coding region for the ccdB (control of cell death) gene.
Derived from luxICDABEG operon terminator of Vibrio fischeri <genbank>AF170104</genbank>.
Bidirectional transcriptional terminator consisting of a 22 bp stem-loop.
In the naturally-occuring sequence there is a mismatch in the stem of the stem loop. This can be corrected via an A->G mutation (at position 40 -- sequence coordinate/not MFOLD coordinate). The above sequence does not reflect this mutation (but the MFOLD image does). This terminator's location cannot be found using some inverted repeat detectors like PALINDROME because it is too short and contains a mismatch. This one was found with the help of Tom Knight. It lies between two coding regions that point towards eachother.
Derived from the TE terminator of T7 bacteriophage between Genes 1.3 and 1.4 <genbank>V01146</genbank>.
Transcription terminator for the E.coli RNA polymerase.
Suggested by Sri Kosuri and Drew Endy as a high efficiency terminator. The 5' end cutoff was placed immediately after the TAA stop codon and the 3' end cutoff was placed just prior to the RBS of Gene 1.4 (before AAGGAG). Use anywhere transcription should be stopped when the gene of interest is upstream of this terminator.
Transcriptional terminator consisting of a 64 bp stem-loop.
Conversion of the iGEM parts registry to SBOL2.1