Difference between revisions of "Part:BBa K4011004"
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===Usage and Biology===
 
===Usage and Biology===
 
TnaA is an tryptophanase found in <i>E. coli</i>. It converts tryptophan (trp) and other related molecules, such as 6-Halogen-trp (6-X-trp) into indole or 6-X-indole. Its specific reaction formula is L-tryptophan + H₂O ⇌ indole + pyruvate + NH₃. Indole, play important roles in signaling in bacterial cells. FMO is a monooxygenase found in <i>Methylophaga aminisulfidivorans</i>. It adds a hydroxyl group onto numerous molecules, in our case adding a hydroxyl onto the third carbon on indole or 6-X-indole, allowing for spontaneous dimerization of 3-hydroxyl-indole or 3-hydroxyl-6-X-indole into indigo or tyrian purple dyes. They are fused together with the common rigid linker EAAAKEAAAK (Lee et al, 2021).  
 
TnaA is an tryptophanase found in <i>E. coli</i>. It converts tryptophan (trp) and other related molecules, such as 6-Halogen-trp (6-X-trp) into indole or 6-X-indole. Its specific reaction formula is L-tryptophan + H₂O ⇌ indole + pyruvate + NH₃. Indole, play important roles in signaling in bacterial cells. FMO is a monooxygenase found in <i>Methylophaga aminisulfidivorans</i>. It adds a hydroxyl group onto numerous molecules, in our case adding a hydroxyl onto the third carbon on indole or 6-X-indole, allowing for spontaneous dimerization of 3-hydroxyl-indole or 3-hydroxyl-6-X-indole into indigo or tyrian purple dyes. They are fused together with the common rigid linker EAAAKEAAAK (Lee et al, 2021).  
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===Characterization===
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TnaA and FMO are two vital but separate enzymes for converting trp/6-Br-trp to our indigo and tyrian purple dye. To increase the overall reaction speed, we fused these two proteins together into TnaA-linker-FMO.
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We designed and engineered three strains of <i>E. coli DH5α ΔTnaA</i>: ptac-TnaA-rbs-FMO (RBS; in this strain TnaA and FMO are expressed as separate proteins), ptac-TnaA-rigid linker-FMO (RL), and ptac-TnaA-Flexible linker-FMO (FL) (Fig. 1A & C). As TnaA is expressed as a tetramer and FMO a dimer, we put the TnaA tetramer at the center of the fused protein, with FMO forming two dimers to each side of the TnaA tetramer (Fig. 1B).
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After culturing and inducing the expression, the three strains, the SDS-PAGE showed separate expression of TnaA (60kDa) and FMO (54kDa) for RBS, and expression of one fused protein at 114 kDa for RL and FL (Fig. 1D). This indicated that our fused proteins are expressed as expected.
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We then cultured and induced RBS, RL, and FL with IPTG. After 20 hours, 1mM of either trp, 6-Cl-trp, or 6-Br-trp was added as substrate, and the relative dye concentration produced by each strain was calculated by using a standard calibration curve (Fig. 2B). The comparison between RBS, RL, and FL shows that there is similar production of tyrian red and tyrian purple, and a significant difference between indigo production of RL and FL. Titers of indigo is approximately 0.30mM (60% yield) for FL and RBS, and 0.20mM (40% yield) for RL. Titers of tyrian red is approximately 0.30mM (60% yield) for RL, FL, and RBS. Titers of tyrian purple is approx. 0.25mM (50% yield) for FL and 0.20mM (40% yield) for RL and RBS.
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After confirming the efficacy of Fre-SttH and TnaA-FMO, we wanted to compare TnaA-rbs-FMO with our TnaA-FL-FMO. Therefore, drawing inspiration from GreatBaySZ 2019’s TnaA-rbs-FMO <partinfo>BBa_K3264022</partinfo> expression system using a constitutive promoter system(TALEsp2), we designed and constructed TALEsp2-TnaA-FL-FMO.
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Instead of using 1mM standard samples of trp or 6-X-trp, we attempted to produce dyes from trp and NaX salts. We induced Fre-SttH expression, took the sample supernatant and added it to the ptac-TnaA-FMO and TALEsp2-TnaA-FMO cultures, and compared the titers of the all using supernatant from Fre-SttH cultures as substrate (Fig. 3).There is no significant difference between any of the samples. Both TALEsp2 cultures produced titers of approx. 0.09mM for tyrian purple and 0.23mM for 6, 6’di-chloro-indigo. RL, FL, and RBS both achieved titers of 0.12 and 0.28mM for tyrian purple and tyrian red respectively.
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Revision as of 09:38, 21 October 2021

TnaA-FL-FMO


Assembly Compatibility:
  • 10
    COMPATIBLE WITH RFC[10]
  • 12
    COMPATIBLE WITH RFC[12]
  • 21
    INCOMPATIBLE WITH RFC[21]
    Illegal BamHI site found at 2812
  • 23
    COMPATIBLE WITH RFC[23]
  • 25
    INCOMPATIBLE WITH RFC[25]
    Illegal AgeI site found at 1219
  • 1000
    COMPATIBLE WITH RFC[1000]

Usage and Biology

TnaA is an tryptophanase found in E. coli. It converts tryptophan (trp) and other related molecules, such as 6-Halogen-trp (6-X-trp) into indole or 6-X-indole. Its specific reaction formula is L-tryptophan + H₂O ⇌ indole + pyruvate + NH₃. Indole, play important roles in signaling in bacterial cells. FMO is a monooxygenase found in Methylophaga aminisulfidivorans. It adds a hydroxyl group onto numerous molecules, in our case adding a hydroxyl onto the third carbon on indole or 6-X-indole, allowing for spontaneous dimerization of 3-hydroxyl-indole or 3-hydroxyl-6-X-indole into indigo or tyrian purple dyes. They are fused together with the common rigid linker EAAAKEAAAK (Lee et al, 2021).

Characterization

TnaA and FMO are two vital but separate enzymes for converting trp/6-Br-trp to our indigo and tyrian purple dye. To increase the overall reaction speed, we fused these two proteins together into TnaA-linker-FMO.

We designed and engineered three strains of E. coli DH5α ΔTnaA: ptac-TnaA-rbs-FMO (RBS; in this strain TnaA and FMO are expressed as separate proteins), ptac-TnaA-rigid linker-FMO (RL), and ptac-TnaA-Flexible linker-FMO (FL) (Fig. 1A & C). As TnaA is expressed as a tetramer and FMO a dimer, we put the TnaA tetramer at the center of the fused protein, with FMO forming two dimers to each side of the TnaA tetramer (Fig. 1B).

After culturing and inducing the expression, the three strains, the SDS-PAGE showed separate expression of TnaA (60kDa) and FMO (54kDa) for RBS, and expression of one fused protein at 114 kDa for RL and FL (Fig. 1D). This indicated that our fused proteins are expressed as expected.

We then cultured and induced RBS, RL, and FL with IPTG. After 20 hours, 1mM of either trp, 6-Cl-trp, or 6-Br-trp was added as substrate, and the relative dye concentration produced by each strain was calculated by using a standard calibration curve (Fig. 2B). The comparison between RBS, RL, and FL shows that there is similar production of tyrian red and tyrian purple, and a significant difference between indigo production of RL and FL. Titers of indigo is approximately 0.30mM (60% yield) for FL and RBS, and 0.20mM (40% yield) for RL. Titers of tyrian red is approximately 0.30mM (60% yield) for RL, FL, and RBS. Titers of tyrian purple is approx. 0.25mM (50% yield) for FL and 0.20mM (40% yield) for RL and RBS.

After confirming the efficacy of Fre-SttH and TnaA-FMO, we wanted to compare TnaA-rbs-FMO with our TnaA-FL-FMO. Therefore, drawing inspiration from GreatBaySZ 2019’s TnaA-rbs-FMO BBa_K3264022 expression system using a constitutive promoter system(TALEsp2), we designed and constructed TALEsp2-TnaA-FL-FMO.

Instead of using 1mM standard samples of trp or 6-X-trp, we attempted to produce dyes from trp and NaX salts. We induced Fre-SttH expression, took the sample supernatant and added it to the ptac-TnaA-FMO and TALEsp2-TnaA-FMO cultures, and compared the titers of the all using supernatant from Fre-SttH cultures as substrate (Fig. 3).There is no significant difference between any of the samples. Both TALEsp2 cultures produced titers of approx. 0.09mM for tyrian purple and 0.23mM for 6, 6’di-chloro-indigo. RL, FL, and RBS both achieved titers of 0.12 and 0.28mM for tyrian purple and tyrian red respectively.