Coding

Part:BBa_K3711002

Designed by: Jiacheng Shi   Group: iGEM21_HUST-China   (2021-10-01)
Revision as of 09:52, 21 October 2021 by Wangbohan (Talk | contribs)

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ROX1

Rox1 is a repressor that targets the promotor of anb1


A kind of yeast protein, which could inhibit promoter Panb1 and then silence following genes of it. Sequence and Features


Assembly Compatibility:
  • 10
    COMPATIBLE WITH RFC[10]
  • 12
    INCOMPATIBLE WITH RFC[12]
    Illegal NotI site found at 1244
  • 21
    COMPATIBLE WITH RFC[21]
  • 23
    COMPATIBLE WITH RFC[23]
  • 25
    COMPATIBLE WITH RFC[25]
  • 1000
    INCOMPATIBLE WITH RFC[1000]
    Illegal BsaI site found at 163
    Illegal SapI site found at 422


Molecular cloning

Plasmid with target gene is transformed into E.coli. From them, we acquire large amount of target gene using as raw material for further operation.

Fig1. Colony PCR result of AOX1-α factor-ROX1-AOX1 Terminator transformed E.coli

The band of AOX1-α factor-ROX1-AOX1 Terminator from colony PCR is about 3000bp, identical to the theoretical length of 3070bp estimated by the designed primer location (promoter to terminator), which could demonstrate that this target plasmid had successfully transformed into E.coli
AOX1 promoter is the strongest eukaryotic promoter currently known in yeast expression system. So we choose AOX1 as the primary promoter when we synthesized all these plasmid for the sake of more convenient expression. But noticing that methanol is hazardous, flammable, combustible and therefore, inappropriate to have direct contact with the hair, we need to substrate AOX1 for constitutive promoter Panb1 and xylose induced promoter Pynr071C to realize the projected regulation function as designed.

Fig2. Plasmid construction and colony PCR results of Panb1-α factor-FMO-AOX1 Terminator and Pynr071c-α factor-ROX1-AOX1 Terminator transformed E.coli

The bands of Panb1-α factor-FMO-AOX1 Terminator (less than 3000bp) and Pynr071c-α factor-ROX1-AOX1 Terminator (3000+bp) from colony PCR are identical to the theoretical lengths of 2676bp and 3321bp estimated by the designed primer locations (promoter to terminator), which could demonstrate that these target plasmid are successfully constructed.

SDS-PAGE

During the test, we find a vague band of ROX1 which couldn’t be verified as successfully expressed according to its SDS-PAGE result in the supernatant. As the key component of our xylose responding system, the successful expression of ROX1 is most vital to our project, so we apply purification through Nickel-affinity chromatography column to ROX1 to further identify its expression. Lucky us, target band is acquired and confirmed. It feels so good to announce that our ROX1 can be expressed like the others.

Fig3. SDS-PAGE result of ROX1 after purification through Nickel-affinity chromatography column

Different from impure or permeate bands, the target protein located around 55-55kDa, bigger than the theoretical 47.09kDa but still within explainable and acceptable range of glycosylation modification. ROX1 could be confirmed as successfully expressed. Although no gradient elution is applied, following elution result could verify this is ROX1, with some impurity bands occurring in the first ROX1 elution.

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