<p>Biofilm formation on surfaces is an issue in the medical field, naval industry, and other areas. We developed an anti-fouling peptide with two modular components: a mussel adhesion protein (MAP) anchor and LL-37, an antimicrobial peptide. MAPs can selectively attach to metal and organic surfaces via L-3,5-dihydroxyphenylalanine (L-DOPA), a nonstandard amino acid that was incorporated using a genetically recoded organism (GRO). Because this peptide is toxic to the GRO in which it is produced, we designed a better controlled inducible system that limits basal expression. This was achieved through a novel T7 riboregulation system that controls expression at both the transcriptional and translational levels.</p>
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<p>This week served as an orientation and planning period. The graduate mentors showed us around our lab space, and we practiced some lab techniques (such as proper aseptic technique and a transformation protocol in E. coli) with the Isaacs lab graduate students. The plan is to begin working with our rhizobia strains (Sinorhizobium meliloti 1021 and Rhizobium tropici CIAT) next week; we ordered some cyanobacterium Synechococcus sp. PCC 7002 from the Pasteur collection, but it is backordered and may take some weeks to arrive.</p>
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<p>Biofilm formation on surfaces is an issue in the medical field, naval industry, and other areas. We developed an anti-fouling peptide with two modular components: a mussel adhesion protein (MAP) anchor and LL-37, an antimicrobial peptide. MAPs can selectively attach to metal and organic surfaces via L-3,5-dihydroxyphenylalanine (L-DOPA), a nonstandard amino acid that was incorporated using a genetically recoded organism (GRO). Because this peptide is toxic to the GRO in which it is produced, we designed a better controlled inducible system that limits basal expression. This was achieved through a novel T7 riboregulation system that controls expression at both the transcriptional and translational levels.</p>
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<p>We laid out a series of experiments which would eventually allow us to express a nonspecific recombinase (beta-homolog) to incorporate foreign DNA into our organism's genome; this process is at the heart of the MAGE technique. Much of this week was spent identifying recombinases which could potentially function in our organisms through literature and BLAST searches. We also spent a significant amount of time identifying inducible promoters (either native to our organisms or within the BioBrick Registry) which we could use to express our recombinase.</p>
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<p>The first step in our plan is to determine optimal growth conditions, transformation protocols, and selection screens for our strains. Once this is complete, we can test the effectiveness of our identified promoters by placing them upstream of a fluorescent reporter; we will use the yellow-fluorescent citrine protein since its emission wavelength does not overlap with the autofluorescence wavelengths of our cyanobacteria. After identifying the most effective promoter (lowest leakiness and highest expression level when induced), we can replace the citrine gene in our construct with our synthesized beta-homolog genes. Testing the effectiveness of our recombinases will be a bit of a challenge; we need an assay to be implemented in each organism that will allow us to quantify mutagenesis efficiency.</p>
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<p>While all of this is going on, we will also need to knock out the mutS gene in each of our organisms. mutS is involved in identifying nucleotide mismatches during DNA replication. Since MAGE is founded upon such mismatches, it is in our best interest to allow them to go unnoticed by the cell's DNA proofreading systems. Silencing mutS should allow us to do this.</p>
<p class="text-center"><a href="dropbox.com/#week2" class="file__link">Go to the Lab Notebook</a></p>
<p class="text-center"><a href="dropbox.com/#week2" class="file__link">Go to the Lab Notebook</a></p>
Dan began his research for the summer two weeks before the other researchers arrived. This was the first week any iGEM researcher was in the lab, so it was focused on preparing the lab and assessing the viability of two of our possible projects. The project which was started this week focused on porting Multiplex Automated Genome Engineering (MAGE) from E. Coli, in which the technique is proven to work, to Cyanobacteria and Sinorhizobium bacteria.
In order to port MAGE from E. Coli to other organisms, we had to first find inducible promoters that worked in Cyanobacteria and Sinorhizobia, and then beta-homolog proteins (reference to MAGE section of our wiki) for both organisms. At this point in the project, we began with finding cyanobacterial inducible promoters. We found promoters in Cyanobacteria which should, in theory, be inducible, and one constitutive promoter. The promoters were a nitrate-inducible promoter nirA, an iron-inducible promoter isiAB, a green-light-inducible promoter pCpG2, and a constitutive promoter, psaA. We designed and ordered primers to isolate all of these promoters from their respective backbones, whether they were Synechococcus sp. 7002 or Synechocystis sp. 6803. We also focused our efforts on growing up copies of a backbone plasmid, BBa_K125000, which was to contain our primers.
This week served as an orientation and planning period. The graduate mentors showed us around our lab space, and we practiced some lab techniques (such as proper aseptic technique and a transformation protocol in E. coli) with the Isaacs lab graduate students. The plan is to begin working with our rhizobia strains (Sinorhizobium meliloti 1021 and Rhizobium tropici CIAT) next week; we ordered some cyanobacterium Synechococcus sp. PCC 7002 from the Pasteur collection, but it is backordered and may take some weeks to arrive.
We laid out a series of experiments which would eventually allow us to express a nonspecific recombinase (beta-homolog) to incorporate foreign DNA into our organism's genome; this process is at the heart of the MAGE technique. Much of this week was spent identifying recombinases which could potentially function in our organisms through literature and BLAST searches. We also spent a significant amount of time identifying inducible promoters (either native to our organisms or within the BioBrick Registry) which we could use to express our recombinase.
The first step in our plan is to determine optimal growth conditions, transformation protocols, and selection screens for our strains. Once this is complete, we can test the effectiveness of our identified promoters by placing them upstream of a fluorescent reporter; we will use the yellow-fluorescent citrine protein since its emission wavelength does not overlap with the autofluorescence wavelengths of our cyanobacteria. After identifying the most effective promoter (lowest leakiness and highest expression level when induced), we can replace the citrine gene in our construct with our synthesized beta-homolog genes. Testing the effectiveness of our recombinases will be a bit of a challenge; we need an assay to be implemented in each organism that will allow us to quantify mutagenesis efficiency.
While all of this is going on, we will also need to knock out the mutS gene in each of our organisms. mutS is involved in identifying nucleotide mismatches during DNA replication. Since MAGE is founded upon such mismatches, it is in our best interest to allow them to go unnoticed by the cell's DNA proofreading systems. Silencing mutS should allow us to do this.
Biofilm formation on surfaces is an issue in the medical field, naval industry, and other areas. We developed an anti-fouling peptide with two modular components: a mussel adhesion protein (MAP) anchor and LL-37, an antimicrobial peptide. MAPs can selectively attach to metal and organic surfaces via L-3,5-dihydroxyphenylalanine (L-DOPA), a nonstandard amino acid that was incorporated using a genetically recoded organism (GRO). Because this peptide is toxic to the GRO in which it is produced, we designed a better controlled inducible system that limits basal expression. This was achieved through a novel T7 riboregulation system that controls expression at both the transcriptional and translational levels.
Biofilm formation on surfaces is an issue in the medical field, naval industry, and other areas. We developed an anti-fouling peptide with two modular components: a mussel adhesion protein (MAP) anchor and LL-37, an antimicrobial peptide. MAPs can selectively attach to metal and organic surfaces via L-3,5-dihydroxyphenylalanine (L-DOPA), a nonstandard amino acid that was incorporated using a genetically recoded organism (GRO). Because this peptide is toxic to the GRO in which it is produced, we designed a better controlled inducible system that limits basal expression. This was achieved through a novel T7 riboregulation system that controls expression at both the transcriptional and translational levels.
Biofilm formation on surfaces is an issue in the medical field, naval industry, and other areas. We developed an anti-fouling peptide with two modular components: a mussel adhesion protein (MAP) anchor and LL-37, an antimicrobial peptide. MAPs can selectively attach to metal and organic surfaces via L-3,5-dihydroxyphenylalanine (L-DOPA), a nonstandard amino acid that was incorporated using a genetically recoded organism (GRO). Because this peptide is toxic to the GRO in which it is produced, we designed a better controlled inducible system that limits basal expression. This was achieved through a novel T7 riboregulation system that controls expression at both the transcriptional and translational levels.
Biofilm formation on surfaces is an issue in the medical field, naval industry, and other areas. We developed an anti-fouling peptide with two modular components: a mussel adhesion protein (MAP) anchor and LL-37, an antimicrobial peptide. MAPs can selectively attach to metal and organic surfaces via L-3,5-dihydroxyphenylalanine (L-DOPA), a nonstandard amino acid that was incorporated using a genetically recoded organism (GRO). Because this peptide is toxic to the GRO in which it is produced, we designed a better controlled inducible system that limits basal expression. This was achieved through a novel T7 riboregulation system that controls expression at both the transcriptional and translational levels.
Biofilm formation on surfaces is an issue in the medical field, naval industry, and other areas. We developed an anti-fouling peptide with two modular components: a mussel adhesion protein (MAP) anchor and LL-37, an antimicrobial peptide. MAPs can selectively attach to metal and organic surfaces via L-3,5-dihydroxyphenylalanine (L-DOPA), a nonstandard amino acid that was incorporated using a genetically recoded organism (GRO). Because this peptide is toxic to the GRO in which it is produced, we designed a better controlled inducible system that limits basal expression. This was achieved through a novel T7 riboregulation system that controls expression at both the transcriptional and translational levels.
Biofilm formation on surfaces is an issue in the medical field, naval industry, and other areas. We developed an anti-fouling peptide with two modular components: a mussel adhesion protein (MAP) anchor and LL-37, an antimicrobial peptide. MAPs can selectively attach to metal and organic surfaces via L-3,5-dihydroxyphenylalanine (L-DOPA), a nonstandard amino acid that was incorporated using a genetically recoded organism (GRO). Because this peptide is toxic to the GRO in which it is produced, we designed a better controlled inducible system that limits basal expression. This was achieved through a novel T7 riboregulation system that controls expression at both the transcriptional and translational levels.
Biofilm formation on surfaces is an issue in the medical field, naval industry, and other areas. We developed an anti-fouling peptide with two modular components: a mussel adhesion protein (MAP) anchor and LL-37, an antimicrobial peptide. MAPs can selectively attach to metal and organic surfaces via L-3,5-dihydroxyphenylalanine (L-DOPA), a nonstandard amino acid that was incorporated using a genetically recoded organism (GRO). Because this peptide is toxic to the GRO in which it is produced, we designed a better controlled inducible system that limits basal expression. This was achieved through a novel T7 riboregulation system that controls expression at both the transcriptional and translational levels.
Biofilm formation on surfaces is an issue in the medical field, naval industry, and other areas. We developed an anti-fouling peptide with two modular components: a mussel adhesion protein (MAP) anchor and LL-37, an antimicrobial peptide. MAPs can selectively attach to metal and organic surfaces via L-3,5-dihydroxyphenylalanine (L-DOPA), a nonstandard amino acid that was incorporated using a genetically recoded organism (GRO). Because this peptide is toxic to the GRO in which it is produced, we designed a better controlled inducible system that limits basal expression. This was achieved through a novel T7 riboregulation system that controls expression at both the transcriptional and translational levels.
Biofilm formation on surfaces is an issue in the medical field, naval industry, and other areas. We developed an anti-fouling peptide with two modular components: a mussel adhesion protein (MAP) anchor and LL-37, an antimicrobial peptide. MAPs can selectively attach to metal and organic surfaces via L-3,5-dihydroxyphenylalanine (L-DOPA), a nonstandard amino acid that was incorporated using a genetically recoded organism (GRO). Because this peptide is toxic to the GRO in which it is produced, we designed a better controlled inducible system that limits basal expression. This was achieved through a novel T7 riboregulation system that controls expression at both the transcriptional and translational levels.
Biofilm formation on surfaces is an issue in the medical field, naval industry, and other areas. We developed an anti-fouling peptide with two modular components: a mussel adhesion protein (MAP) anchor and LL-37, an antimicrobial peptide. MAPs can selectively attach to metal and organic surfaces via L-3,5-dihydroxyphenylalanine (L-DOPA), a nonstandard amino acid that was incorporated using a genetically recoded organism (GRO). Because this peptide is toxic to the GRO in which it is produced, we designed a better controlled inducible system that limits basal expression. This was achieved through a novel T7 riboregulation system that controls expression at both the transcriptional and translational levels.
Biofilm formation on surfaces is an issue in the medical field, naval industry, and other areas. We developed an anti-fouling peptide with two modular components: a mussel adhesion protein (MAP) anchor and LL-37, an antimicrobial peptide. MAPs can selectively attach to metal and organic surfaces via L-3,5-dihydroxyphenylalanine (L-DOPA), a nonstandard amino acid that was incorporated using a genetically recoded organism (GRO). Because this peptide is toxic to the GRO in which it is produced, we designed a better controlled inducible system that limits basal expression. This was achieved through a novel T7 riboregulation system that controls expression at both the transcriptional and translational levels.
Biofilm formation on surfaces is an issue in the medical field, naval industry, and other areas. We developed an anti-fouling peptide with two modular components: a mussel adhesion protein (MAP) anchor and LL-37, an antimicrobial peptide. MAPs can selectively attach to metal and organic surfaces via L-3,5-dihydroxyphenylalanine (L-DOPA), a nonstandard amino acid that was incorporated using a genetically recoded organism (GRO). Because this peptide is toxic to the GRO in which it is produced, we designed a better controlled inducible system that limits basal expression. This was achieved through a novel T7 riboregulation system that controls expression at both the transcriptional and translational levels.
Biofilm formation on surfaces is an issue in the medical field, naval industry, and other areas. We developed an anti-fouling peptide with two modular components: a mussel adhesion protein (MAP) anchor and LL-37, an antimicrobial peptide. MAPs can selectively attach to metal and organic surfaces via L-3,5-dihydroxyphenylalanine (L-DOPA), a nonstandard amino acid that was incorporated using a genetically recoded organism (GRO). Because this peptide is toxic to the GRO in which it is produced, we designed a better controlled inducible system that limits basal expression. This was achieved through a novel T7 riboregulation system that controls expression at both the transcriptional and translational levels.
Biofilm formation on surfaces is an issue in the medical field, naval industry, and other areas. We developed an anti-fouling peptide with two modular components: a mussel adhesion protein (MAP) anchor and LL-37, an antimicrobial peptide. MAPs can selectively attach to metal and organic surfaces via L-3,5-dihydroxyphenylalanine (L-DOPA), a nonstandard amino acid that was incorporated using a genetically recoded organism (GRO). Because this peptide is toxic to the GRO in which it is produced, we designed a better controlled inducible system that limits basal expression. This was achieved through a novel T7 riboregulation system that controls expression at both the transcriptional and translational levels.
Biofilm formation on surfaces is an issue in the medical field, naval industry, and other areas. We developed an anti-fouling peptide with two modular components: a mussel adhesion protein (MAP) anchor and LL-37, an antimicrobial peptide. MAPs can selectively attach to metal and organic surfaces via L-3,5-dihydroxyphenylalanine (L-DOPA), a nonstandard amino acid that was incorporated using a genetically recoded organism (GRO). Because this peptide is toxic to the GRO in which it is produced, we designed a better controlled inducible system that limits basal expression. This was achieved through a novel T7 riboregulation system that controls expression at both the transcriptional and translational levels.
Biofilm formation on surfaces is an issue in the medical field, naval industry, and other areas. We developed an anti-fouling peptide with two modular components: a mussel adhesion protein (MAP) anchor and LL-37, an antimicrobial peptide. MAPs can selectively attach to metal and organic surfaces via L-3,5-dihydroxyphenylalanine (L-DOPA), a nonstandard amino acid that was incorporated using a genetically recoded organism (GRO). Because this peptide is toxic to the GRO in which it is produced, we designed a better controlled inducible system that limits basal expression. This was achieved through a novel T7 riboregulation system that controls expression at both the transcriptional and translational levels.
Biofilm formation on surfaces is an issue in the medical field, naval industry, and other areas. We developed an anti-fouling peptide with two modular components: a mussel adhesion protein (MAP) anchor and LL-37, an antimicrobial peptide. MAPs can selectively attach to metal and organic surfaces via L-3,5-dihydroxyphenylalanine (L-DOPA), a nonstandard amino acid that was incorporated using a genetically recoded organism (GRO). Because this peptide is toxic to the GRO in which it is produced, we designed a better controlled inducible system that limits basal expression. This was achieved through a novel T7 riboregulation system that controls expression at both the transcriptional and translational levels.
Biofilm formation on surfaces is an issue in the medical field, naval industry, and other areas. We developed an anti-fouling peptide with two modular components: a mussel adhesion protein (MAP) anchor and LL-37, an antimicrobial peptide. MAPs can selectively attach to metal and organic surfaces via L-3,5-dihydroxyphenylalanine (L-DOPA), a nonstandard amino acid that was incorporated using a genetically recoded organism (GRO). Because this peptide is toxic to the GRO in which it is produced, we designed a better controlled inducible system that limits basal expression. This was achieved through a novel T7 riboregulation system that controls expression at both the transcriptional and translational levels.
Biofilm formation on surfaces is an issue in the medical field, naval industry, and other areas. We developed an anti-fouling peptide with two modular components: a mussel adhesion protein (MAP) anchor and LL-37, an antimicrobial peptide. MAPs can selectively attach to metal and organic surfaces via L-3,5-dihydroxyphenylalanine (L-DOPA), a nonstandard amino acid that was incorporated using a genetically recoded organism (GRO). Because this peptide is toxic to the GRO in which it is produced, we designed a better controlled inducible system that limits basal expression. This was achieved through a novel T7 riboregulation system that controls expression at both the transcriptional and translational levels.
Biofilm formation on surfaces is an issue in the medical field, naval industry, and other areas. We developed an anti-fouling peptide with two modular components: a mussel adhesion protein (MAP) anchor and LL-37, an antimicrobial peptide. MAPs can selectively attach to metal and organic surfaces via L-3,5-dihydroxyphenylalanine (L-DOPA), a nonstandard amino acid that was incorporated using a genetically recoded organism (GRO). Because this peptide is toxic to the GRO in which it is produced, we designed a better controlled inducible system that limits basal expression. This was achieved through a novel T7 riboregulation system that controls expression at both the transcriptional and translational levels.
