Composite
GRHPR-AIDA

Part:BBa_K3332059

Designed by: Qingliu Wang   Group: iGEM20_XMU-China   (2020-10-17)


J23100-RBS-GRHPR-AIDA-terminator

        We anchor GRHPR protein onto membranes through AIDA to catalyze the reaction of consuming glyoxalic acid and forming NADPH. We use BBa_K880005 to construct the expression system and anchor GRHPR on the surface of E.coli.


Biology

        AIDA is an anchor protein from E. coli, which has been widely used in cell-surface display. GRHPR, a glyoxylate reductase from human liver, can reduce glyoxylic acid when NADPH is used as cofactor.

        GRHPR is fused at C terminal with AIDA so that GRHPR can be displayed on the surface of E. coli.[1][2]

Fig 1. mechanism

Usage

        Here, we used BBa_K880005 to construct the expression system and demonstrated the effect of GRHPR-AIDA on the surface of E. coli. We obtained the composite part BBa_K3332059 and transformed the constructed plasmid into E. coli BL21 (DE3) to verify its expression. The positive clones were cultivated.

Fig 2. Gene circuit of GRHPR-AIDA.

Characterization

1.Identification

        After receiving the synthesized DNA, restriction digestion was done to certify that the plasmid was correct, and the experimental results were shown in figure 3.

Fig 3.DNA gel electrophoresis of restriction digest products of GRHPR-AIDA-pSB1C3 (Xbal I & Pst I sites)

2.Ability of consuming NADPH

        We mixed glyoxylic acid solution, NADPH solution and bacteria solution carrying GRHPR-AIDA. Then, we immediately measured OD340 changes. TECAN® Infinite M200 Pro was used to detect OD340 . And when NADPH is consumed, OD340 declines.

        We successfully got OD340-Time curves of GRHPR fused with 4 types of anchor protein. When using bacteria carrying GRHPR-AIDA, we could see OD340 decreased as the reaction went on. However, by using bacteria carrying J23100-RBS (BBa_K880005) and GRHPR-Histag as control, we could also find that the slopes of these three curves are similar. The results show that our fusion protein GRHPR-AIDA do not work well. The result is shown in figure 4.

Fig 4. OD340-Time curves of GRHPR fused with 4 types of anchor protein


References

  1. ↑ Rumsby G, Cregeen D P. Identification and expression of a cDNA for human hydroxypyruvate/glyoxylate reductase[J]. Biochimica et Biophysica Acta (BBA) - Gene Structure and Expression, 1999, 1446(3): 383-388.
  2. ↑ http://2016.igem.org/Team:TJUSLS_China


Sequence and Features


Assembly Compatibility:
  • 10
    COMPATIBLE WITH RFC[10]
  • 12
    INCOMPATIBLE WITH RFC[12]
    Illegal NheI site found at 7
    Illegal NheI site found at 30
  • 21
    INCOMPATIBLE WITH RFC[21]
    Illegal BamHI site found at 2325
  • 23
    COMPATIBLE WITH RFC[23]
  • 25
    INCOMPATIBLE WITH RFC[25]
    Illegal AgeI site found at 608
  • 1000
    COMPATIBLE WITH RFC[1000]


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