Part:BBa_K5439001
TjPCs (phytochelatin synthase) coding sequence
Phytochelatin synthase coding sequence from Thlaspi japonicum. This gluthanione-γ-glutamylcysteinyltransferase posttranslationally synthesizes phytochelatins in the presence of heavy metals and gluthanione as a mechanism of heavy metal detoxification.
Sequence and Features
- 10COMPATIBLE WITH RFC[10]
- 12INCOMPATIBLE WITH RFC[12]Illegal NheI site found at 181
- 21INCOMPATIBLE WITH RFC[21]Illegal BglII site found at 31
Illegal BglII site found at 1440
Illegal XhoI site found at 1462 - 23COMPATIBLE WITH RFC[23]
- 25COMPATIBLE WITH RFC[25]
- 1000COMPATIBLE WITH RFC[1000]
Usage and Biology
The enzyme chosen for the biopart was phytochelatin synthase (EC:2.3.2.15) as a detector for the presence of cadmium. This enzyme catalyzes the synthesis of glutathione (GSH) polymers, or phytochelatins (PCs). These molecules are the most studied chelators for the detoxification of heavy metals in plants, and they serve as high-affinity chelators for the detoxification of heavy metals such as cadmium, zinc, and nickel. PCs bind to these metals through their thiol groups and inactivate them, storing the PC-metal complex in the cytosol (in the case of plants) or in chloroplasts (in the case of algae or protists) (Rea, 2012; García-García, 2014).
The PCs from Thlaspi japonicum (TjPCs) provides cadmium tolerance when it is heterologous expressed in Saccharomyces cerevisiae, making the synthesis of this enzyme of interest for Cd pollution problems (Mizuno et al., 2003).
Cloning TjPCs insert into pET28b(+) vector
In order heterologously overexpress PCs in Escherichia coli, a ligation was carried out with TjPCs and a vector pET28b(+). This was achieved with T4 DNA ligase (Invitrogen), with molar ratios 3:1 and 5:1 following the protocol obseved in Table 1.
Reagent | Volume (µL) 3:1 ratio | Volume (µL) 5:1 ratio |
---|---|---|
pet28b(+) | 6.7 µL | 6.7 µL |
TjPCs | 5.8 µL | 9.7 µL |
T4 DNA Ligase Buffer | 2 µL | 2 µL |
T4 DNA ligase | 0.2 µL | 0.2 µL |
Nuclease-free water | 5.3 µL | 1.4 µL |
None |