Quorum Sensing

2 Materials

1. Virtual screening (DOCK 6) was performed using a Linux-
   based cluster.


2. Visualization (PyMOL 0.99, HBPLUS 3.06, and Ligplot
   4.22) was conducted on a dual-Xeon Linux graphical
   workstation.


3. Consensus scoring (FRED 2.2.3) and reanalysis of virtual
   screening (FILTER 2.0.1 and IDEA 8.8) were performed on
   a Windows workstation.


4. Compounds information comes from SPECS chemical
   database.


5. The crystal structure information is based on conformation of
   LuxPQ in complex with AI-2 (PDB entry: 2HJ9).
   6.V. harveyiMM32 (ATCC# BAA-1211).


6. Luria Marine (LM) plates: 1% (wt/vol) bacto-tryptone, 0.5%
   (wt/vol) yeast extract, 2% (wt/vol) sodium chloride, 1.5%
   (wt/vol) agar in distilled water. Sterilize by autoclaving.


7. Autoinducer Bioassay (AB) medium: Dissolve 2.0 g vitamin-
   free casamino acids, 12.3 g magnesium sulfate heptahydrate,
   and 17.5 g sodium chloride in 960 mL of distilled water. Adjust
   pH to 7.5 with potassium hydroxide. After autoclave steriliza-
   tion (121C, 20 min), the medium is cooled to room temper-
   ature. Then the following sterile solutions are added to reach
   1 L: 10 mL of 1 M potassium phosphate buffer pH 7.0, 10 mL
   of 100 mML-arginine solution, 20 mL of 50% (v/v) glycerol
   (seeNote 1).


8. 12 mM FeCl 3 in filter-sterilized water.


9. Antibiotic stock solutions: 50 mg/mL kanamycin in distilled
   water (filter-sterilized); 10 mg/mL chloramphenicol in
   ethanol.


10. Luminometer microplate reader.


11. 96-well microtiter plates.


12. Spectrophotometer.


13. 250 mL conical flasks.


14. Shaking incubator.


15. Freshly synthesized 20μM DPD solution (pH¼7).


16. 4 mM boric acid in filter-sterilized water.


17. Compounds to be tested dissolved in AB medium.

356 Tianyu Jiang et al.