Quorum Sensing

(sharon) #1
(b) GKL reverse primer: 5^0 -CCGACCTTACAAGGATCCT-
CAAGCCGAGAACAGCGCC-3^0.
(c) T7 Pro primer: 5^0 -CGAAATTAATACGACTCACTA-
TAGG-3^0.
(d) T7 Term primer: 50 -GCTAGTTATTGCT-
CAGCGGTGGCAGC-3^0.
(e) Lux forward primer: 5^0 -GAGAGACTCGAGT-
TAATTTTTAAAGTATGGGC-3^0.
(f) Lux reverse primer: 5^0 -CTCTCTGGTACCTCAACTAT-
CAAACGCTTCGG-3^0.
(g) Gm-up primer: 5^0 -TGGAGCAGCAACGATGTTAC-3^0.
(h) Gm-downprimer:5^0 -TGTTAGGTGGCGGTACTTGG-3^0.


  1. Thermocycler.

  2. DNA ladder.

  3. Electrophoresis apparatus for DNA agarose gel.

  4. Electrophoresis apparatus for SDS-PAGE analysis.

  5. DNA and protein ladders.

  6. Enzymes (with appropriate buffers): T4 DNA Ligase, NdeI,
    BamHI, XhoI, KpnI, Mutazyme II (Agilent).

  7. Plasmids: pET15b plasmid (Novagen); pUC18R6K-mini-
    Tn7T-GmRplasmid [1]; pTNS2 plasmid [1]; pBAD33 [8].
    29.E. coliBL21 (DE3) cells (Novagen).
    30.E. coliXL1 Blue cells (Stratagene).

  8. Refrigerated centrifuge.

  9. Shaking incubator.

  10. 200μl, 1.5 ml, and 50 ml tubes.

  11. 2 l conic flasks.

  12. Electroporation cuvettes and apparatus.


3 Methods


3.1 Amplification
and Cloning of thegkl
Lactonase Gene


This method describes amplification and cloning of thegkllacto-
nase gene from the genomic DNA isolated fromG. kaustophilus
HTA426 (GI: 56420041).


  1. Prepare a standard PCR reaction mixture (50μl) containing
    800 nM of the oligonucleotides GKL forward primer and GKL
    reverse primer, and 10 ng of genomic DNA.

  2. Amplify the gene in a thermocycler with the following para-
    meters: 98C for 2 min followed by 30 cycles of 98C for 10 s,


314 Maybelle Kho Go et al.

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