Coding

Part:BBa_K2244003:Design

Designed by: Chen Hong   Group: iGEM17_SSTi-SZGD   (2017-10-18)

TorA-opdA


Assembly Compatibility:
  • 10
    COMPATIBLE WITH RFC[10]
  • 12
    COMPATIBLE WITH RFC[12]
  • 21
    INCOMPATIBLE WITH RFC[21]
    Illegal XhoI site found at 1123
  • 23
    COMPATIBLE WITH RFC[23]
  • 25
    INCOMPATIBLE WITH RFC[25]
    Illegal NgoMIV site found at 220
    Illegal AgeI site found at 415
    Illegal AgeI site found at 754
  • 1000
    COMPATIBLE WITH RFC[1000]


Design Notes

In our project , to enable secretion of OPH (gene product of opdA) to the periplasm of E. coli for the development of live cell biocatalysts, the TorA signal peptide followed by four amino acid residues of the mature TorA protein is fused directly to the N-terminal of OPH domain. TorA signal peptide contains a twin-arginine motif of ‘SRRxFLA’, and a recognition site for type I signal peptidases. Therefore this is an improved part of opdA (BBa_K215090), which has been codon optimized for E. coli chassis.


Source

opdA gene was obtained from the chromosome of Agrobacterium radiobacter. The enzyme opdA encodes is a transposable phosphotriesterase. In addition, opdA-like gene is evolutionary conserved in many bacteria species, i.e. Sphingobium fuliginis, Brevundimonas diminuta, and Mycobacterium genera, which indicates horizontal mobility.

TorA is a twin-arginine signal peptide from E. coli. The twin-arginine system a bacterial protein export pathway with the remarkable ability to transport folded proteins across the cytoplasmic membrane. Proteins, with the N-terminal TorA bearing a consensus motif of SRRxFLK, are targeted to a membrane-embedded Tat translocase. Tat signal pepetides consist of three domains: a positively charged N-terminal domain, a hydrophobic domain, and a C-terminal domain. In E. coli, the Tat translocase consists of TatA, TatB, TatC proteins. TatBC is a signal peptide recognition complex, while TatA complex forms a channel for protein translocation across the cytoplasmic membrane. Tat system is also evolutionary conserved in the chromosomes of many bacteria species, such as Bacillius, Streptococcus, Streptomyces, etc.