Plasmid

Part:BBa_K4630201:Design

Designed by: Shuangwu Wu   Group: iGEM23_WHU-China   (2023-10-10)
Revision as of 17:22, 11 October 2023 by ASHIELIW (Talk | contribs)


The optimized pCas


Assembly Compatibility:
  • 10
    INCOMPATIBLE WITH RFC[10]
    Illegal EcoRI site found at 1344
    Illegal EcoRI site found at 7542
    Illegal EcoRI site found at 11785
    Illegal SpeI site found at 5392
    Illegal PstI site found at 11075
  • 12
    INCOMPATIBLE WITH RFC[12]
    Illegal EcoRI site found at 1344
    Illegal EcoRI site found at 7542
    Illegal EcoRI site found at 11785
    Illegal NheI site found at 1103
    Illegal SpeI site found at 5392
    Illegal PstI site found at 11075
    Illegal NotI site found at 5711
  • 21
    INCOMPATIBLE WITH RFC[21]
    Illegal EcoRI site found at 1344
    Illegal EcoRI site found at 7542
    Illegal EcoRI site found at 11785
    Illegal BglII site found at 4205
    Illegal BamHI site found at 3382
    Illegal BamHI site found at 7476
    Illegal BamHI site found at 11664
  • 23
    INCOMPATIBLE WITH RFC[23]
    Illegal EcoRI site found at 1344
    Illegal EcoRI site found at 7542
    Illegal EcoRI site found at 11785
    Illegal SpeI site found at 5392
    Illegal PstI site found at 11075
  • 25
    INCOMPATIBLE WITH RFC[25]
    Illegal EcoRI site found at 1344
    Illegal EcoRI site found at 7542
    Illegal EcoRI site found at 11785
    Illegal SpeI site found at 5392
    Illegal PstI site found at 11075
    Illegal NgoMIV site found at 10624
    Illegal AgeI site found at 7311
    Illegal AgeI site found at 8973
    Illegal AgeI site found at 11499
  • 1000
    INCOMPATIBLE WITH RFC[1000]
    Illegal BsaI site found at 4231
    Illegal BsaI.rc site found at 4219
    Illegal SapI site found at 7293
    Illegal SapI site found at 10564
    Illegal SapI site found at 10774
    Illegal SapI site found at 11481

As the length of the segments vary, we decided to remove redundant part step by step, especially the functional sgRNA. We designed primers for the backbone to delete the sgRNA sequence using Gibson Assembly and Golden Gate Assembly (fig 1).

Fig. 1The sgRNA-removal design of pCas optimization

We successfully amplified the target sequence of pCas (fig 2a). Subse-quently, we employed Golden Gate Assembly. Then sequencing result unveiled that the sgRNA part of pCas had been removed (fig 2c).

Fig. 2The result of sgRNA deletion in pCas
(a) The white hollow arrow heads indicate target bands. The long fragments for Gibson Assembly and Golden Gate Assembly are expected to be 11610 and 11744 bp, respectively. The regular PCR procedure is effective.
(b) The white hollow arrow heads indicate target pCasop bands. The primers were designed to amplify sequence covering the omitted sgRNA.
(c) Sequencing results were aligned with the original pCas sequence. There is a gap at sgRNA.
(d) Sequencing results were aligned with the designed pCasop sequence.

In the next step, we intend to remove the homologous arm of poxb gene (Fig3). We designed to clone the extremely long fragment using a pair of unique primers and link it into a closed loop using Golden Gate Assembly. Regrettably, only the ultra-long fragment was successfully cloned (Fig4) within the given time constraints, while the connection failed.

Fig. 3The design of Removing Homologous Arm Sequence

Fig. 4 The result of PCR fragment, cloned by removing HA primers

Lanes 1 to 4 consist of parallel groups of amplified ultra-long fragments, with a fragment length of 11744 bp.

Design Notes

The plasmid is temperature sensitive.


As the length of the segments vary, we decided to remove redundant part step by step, especially the functional sgRNA. We designed primers for the backbone to delete the sgRNA sequence using Gibson Assembly and Golden Gate Assembly (fig 1).


Source

Zhao, D., Yuan, S., Xiong, B. et al. Development of a fast and easy method for Escherichia coli genome editing with CRISPR/Cas9. Microb Cell Fact 15, 205 (2016).

References

Zhao, D., Yuan, S., Xiong, B. et al. Development of a fast and easy method for Escherichia coli genome editing with CRISPR/Cas9. Microb Cell Fact 15, 205 (2016).