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Gateway cloning

  1. GATEWAY CLONING SWAPNIL MISHRA M.PHARM ( 1st Sem) NIPER - KOLKATA
  2. GATEWAY CLONING ? This system invented & commercialised by Invitrogen life technologies since the late 1990s. It is a molecular biology method that enables researchers to efficiently transfer DNA fragments between plasmids using an appropriate set of recombination sequences,the ‘Gateway att’ sites & two proprietary enzyme mixes called as “LR clonase” & “BP clonase”.
  3. Your Application Gene1 Gene2 Gene3 Gene4 Your Application Gene Protein Localization Gene Gene Protein Purification Gene RNAi Gene Cell-Free Gene Protein interaction Gene Gene Entry Clone PCR Gene synthesis ORF collection Library Your Source GATEWAY CLONING SYSTEM  Directional cloning  Maintains Reading frame  No restriction enzymes  No ligation  1hr,room temp reaction with >99% efficiency No resequencing  Compatible with automation Reversible reactions
  4. It enables you to access virtually any expression system in just a few steps. It circumvents the roadblocks of traditional restriction enzyme cloning No need for ligase , subcloning steps or the hours spent to screen countless colonies.
  5. ADVANTAGES OF GATEWAY CLONING  Fast reactions- 1hour room temperature cloning reactions.  Accurate result- cloning reactions achieve >95%efficiency to deliver the clone you need.  Versatile technology- easily shuttle DNA material / insert from vector to vector.  Streamlined protocol- no need for resequencing use the same clone from target identification to validation.
  6. BASICS OF GATEWAY CLONING  BP reaction- to create Invitrogen gateway entry clone.  LR reaction- to create a gateway expression clone.  One tube format- to create Gateway expression clone from a pcr product.  Gateway vector conversion- converting your favourite cloning vectors to gateway technology.
  7. BP REACTION • Creating a Gateway entry clone from an attB-flanked PCR product is an easy 1 hour reaction. See below for an overview of the set-up. For more detailed information, refer to the manual. • Add the following components to a 1.5 ml tube at room temperature and mix: attB-PCR product (=10 ng/µl; final amount ~15–150 ng) 1–7 µl Donor vector (150 ng/µl) 1 µl TE buffer, pH 8.0 to 8 µl • Thaw on ice the Invitrogen BP Clonase II enzyme mix for about 2 minutes. Vortex the BP Clonase II enzyme mix briefly twice (2 seconds each time). • To each sample (Step 1, above), add 2 µl of BP Clonase II enzyme mix to the reaction and mix well by vortexing briefly twice. Microcentrifuge briefly. • Return BP Clonase II enzyme mix to –20°C or -80°C storage. • Incubate reactions at 25°C for 1 hour. • Add 1 µl of the Proteinase K solution to each sample to terminate the reaction. Vortex briefly. Incubate samples at 37°C for 10 minutes.
  8. • Transformation • Transform 1 µl of each BP reaction into 50 µl of Invitrogen One Shot OmniMAX 2 Phage-Resistant Cells (Catalog no. C8540-03). Incubate on ice for 30 minutes. shock cells by incubating at 42°C for 30 seconds. Add 250 µl of S.O.C. Medium incubate at 37°C for 1 hour with shaking. Plate 20 µl and 100 µl of each transformation onto selective plates. Note: Any competent cells with a transformation efficiency of >1.0 × 10 8 transformants/µg may be used. • Transform 1 µl of pUC19 DNA (10 ng/ml) into 50 µl of One Shot OmniMAX 2 T1 Phage-Resistant Cells as described above. Plate 20 µl and 100 µl on LB plates containing 100 µg/ml kanamycin, or the appropriate selection marker for your donor vector. • Expected results An efficient BP recombination reaction will produce >1500 colonies if the entire BP reaction is transformed and plated.
  9. BP REACTION
  10. LR REACTION • Transferring your gene from a Gateway entry clone to destination vector is an easy 1 hour reaction. See below for an overview of the set-up. For more detailed information, refer to the manual. • Add the following components to a 1.5 ml tube at room temperature and mix: Entry clone (50-150 ng) 1–7 µl Destination vector (150 ng/µl) 1 µl TE buffer, pH 8.0 to 8 µl • Thaw on ice the Invitrogen LR Clonase II enzyme mix for about 2 minutes. Vortex the LR Clonase II enzyme mix briefly twice (2 seconds each time). • To each sample (Step 1, above), add 2 µl of LR Clonase II enzyme mix to the reaction and mix well by vortexing briefly twice. Microcentrifuge briefly. • Return LR Clonase II enzyme mix to -20°C or -80°C storage. • Incubate reactions at 25°C for 1 hour. • Add 1 µl of the Proteinase K solution to each sample to terminate the reaction. Vortex briefly. Incubate samples at 37°C for 10 minutes. • Transformation Follow the protocol as indicated for the BP reaction, except use the appropriate selection marker for the LB plates suited to your destination vector (typically 100 µg/ml ampicillin). Expected results An efficient LR recombination reaction will produce >5000 colonies if the entire LR reaction is transformed and plated
  11. LR REACTION
  12. ONE TUBE FORMAT • If you want to transfer your attB-flanked PCR product directly into an expression clone, you can easily combine the BP and LR reactions using the following protocol. This will potentially eliminate the transformation and DNA isolation of the Gateway entry clone. • In a 1.5 ml microcentrifuge tube, prepare the following 15 µl BP reaction: attB DNA (50-100 ng) 1.0–5.0 µl attP DNA (Invitrogen pDONR vector, 150 ng/µl) 1.3 µl BP Clonase II enzyme mix 3.0 µl TE Buffer, pH 8.0 add to a final volume of 15 µl • Mix well by vortexing briefly and incubate at 25°C for 4 hours. Note: Depending on your needs, the length of the recombination reaction can be extended up to 20 hours. An overnight incubation typically yields 5 times more colonies than a 1 hour incubation. Longer incubation times are recommended for large plasmids (=10 kb) and PCR products (=5 kb). • Remove 5 µl of the reaction to a separate tube and use this aliquot to assess the efficiency of the BP reaction (see below). • To the remaining 10 µl reaction, add: Destination vector (150 ng/µl) 2.0 µl LR Clonase II enzyme mix 3.0 µl Final volume 15 µl • Mix well by vortexing briefly and incubate at 25°C for 2 hours. Note: Depending on your needs, the length of the recombination reaction can be extended up to 18 hours.
  13. • Add 2 µl of proteinase K solution. Incubate at 37°C for 10 minutes. 1.Transform 50 µl of the appropriate competent E. coli with 1 µl of the reaction. 2.Plate on LB plates containing the appropriate antibiotic to select for expression clones. Assessing the efficiency of the BP reaction 1.To the 5µl aliquot obtained from “One-Tube” Protocol, Step 3, above, add 0.5 µl of proteinase K solution. Incubate at 37°C for 10 minutes. 2.Transform 50 µl of the appropriate competent E. coli with 1 µl of the reaction. Plate on LB plates containing the appropriate antibiotic to select for entry clones.
  14. GATEWAY CONVERSION • Converting your favorite set of cloning vectors to Gateway Technology is a fairly straightforward protocol, and will ultimately allow you to streamline your cloning and expression process. To convert your cloning vector to a Gateway destination vector, you will: • Choose the appropriate reading frame cassette to use depending on your needs. • Linearize the vector you wish to convert with a restriction enzyme of choice. If you use a restriction enzyme that generates an overhang, you will need to blunt the ends. • Remove the 5' phosphates from the vector using calf intestinal alkaline phosphatase. • Ligate the reading frame cassette into your vector using T4 DNA ligase. • Transform the ligation reaction into One Shot ccdB Survival Competent E. coli and select for transformants. • Analyze transformants.
  15. GATEWAY SYSTEM relies on five sets of specific and non cross reacting att sequences. The specificity is given by the 7 nucleotides of the core region.
  16. GATEWAY RECOMBINATION CLONING VS TRADITIONAL RESTRICTION ENZYME CLONING Steps GATEWAY CLONING RESTRICTION ENZYME CLONING Existing primers ? Yes No Vector ready for cloning ? Yes No Ligation reagents included ? Yes No Competent cells separately ? Included Purchase separately: 0 hours Prepare: upto 6hours Vector clean up ? No Yes PCR FRAGMENT cleanup ? No Yes Recombination efficiency ? upto 95% ~50%
  17. GLOSSARY att site- A defined length of DNA that constitutes a recombination site.There are 4 classes of att sites called attB,attP,attL,attR.  ccdB gene- A counterselectable gene that allows for negative selection of unwanted byproduct plasmid after recombination.  Entry(pENTR)clone- A vector that contains your gene of interest flanked by attL or attR sites.  Donor(pDONR)vector- Avector with attP sites flanking a counterselectable gene that recombines with a gene of interest flanked by attB sites.  Destination(DEST)vector- An application geared vector with attR sites flanking a counterselectable gene that will recombine with one or more entry clones.  Multisite Gateway Technology- A system that allows simultaneous assembly of multiple DNA fragments into a single destination vector.
  18. REFERENCE - https://www.embl.de/pepcore/pepcore_services/cloning/cloning_method/recombin ation/gateway/cloning.html https://www.thermofisher.com/in/en/home/life-science/cloning/gateway- cloning.html
  19. THANK YOU
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