Difference between revisions of "Part:BBa K4677001"

Revision as of 23:59, 8 October 2023

TorR

The torR gene of Escherichia coli encodes a 25kD response regulator protein involved in the expression regulation of the trimethylamine N-oxide reductase genes, which are regulated by torCAD operon. The torR gene is located just upstream of the torCAD operon, with an opposite transcription direction. The torR-torCAD intergenic region is unusual in that it contains four direct repeats of a 10-nucleotide motif. Part or all of these motifs could be involved in the binding of TorR protein. TorR only mediate the TMAO induction.

Sequence and Features

In order to construct the standard part pSB1C3-TorR plasmid, TorR sequence was tested to see if there is EcoRI and PstI site. The testing result was shown in Fig.1.

Fig.1 The map of TorR gene sequence described by SnapGene Viewer, showing the restriction enzyme information (no EcoRI and PstI sites).

After testing the restriction enzyme information of TorR gene using SnapGene software, it was inserted into the pSB1C3 plasmid to construct the standard part pSB1C3-TorR with PCR method. Then it was identified as follows:

Fig.2 Identification of standard part pSB1C3-TorR using digestion with EcoRI and PstI, and PCR method. M: Marker; 1: Plasmid; 2: Digestion result; 3: PCR result.

In our project, TorR was expressed in pET28a vector and purified by 6×his tag, After induced expression by IPTG, TorR protein was purified using magnetic beads. The SDS-PAGE electrophorisis result was showed as follows:

Fig.3 The SDS-PAGE result shows expression and purification of TorR protein. M: Marker; 1: All supernatant proteins containing overexpressioned TorR induced by IPTG; 2: Supernatant proteins not bound to magnetic beads in purification process; 3: Proteins in wash buffer; 4: Purified TorR (27kD) protein in elution buffer.