Composite

Part:BBa_K2443038

Designed by: Lethbridge iGEM 2017   Group: iGEM17_Lethbridge   (2017-10-27)
Revision as of 01:49, 2 November 2017 by Graeme.glaister (Talk | contribs)


tRNAPhe-MS2

tRNAPhe-MS2 co-purification construct. Contains a T7 promoter -10 followed by tRNA Phe, two MS2 RNA aptamers and a double terminator. To be used in conjunction with BBa_K2109108.


tRNA Purification


Both BBa K2443038 and BBa_K2109108 were overexpressed individually in E. coli BL21-Gold (DE3) cells. Upon which time the cells were lysed, the lysate combined, and applied to a Nickel Sepharose affinity column. In order to cleave the RNA, 1 µM of DNA oligo was added to the column, as well as varying amounts of RNase H. Incubation times on the column with RNase H and DNA oligo varied from 2 hours (Figure 3) to 12 hours (Figure 4), and the amount of RNase H used varied from 10 units to 100 units (Figure 3 and 4). Based upon the varied conditions, a longer incubation time had the greatest effect on tRNA cleavage efficiency with units of RNase H being optimal between the range of 5-50. With these improvements from our initial attempt at tRNA cleavage we successfully purified tRNAPhe, as shown in Figure 4.

For more information on the design, see the "http://2017.igem.org/Team:Lethbridge/Design#anchor5" tRNA purification</a> section here.

Lethbridge_tRNApurification.png

Figure 3 - Preliminary tRNAPhe Purification. 12% 8M urea PAGE run for 45 mins at 300 V. All concentrated fractions were phenol chloroform extracted, ethanol precipitated and re-suspended in 30 µL of ddH2O. Lanes are as follows: 1- tRNA fraction with 20 units of RNase H added; 2- concentrated tRNA fraction 20 units of RNase H added; 3- concentrated MS2 fraction 1 20 units of RNase H added; 4- concentrated MS2 fraction 2 20 units of RNase H added; 5- tRNA standard (76 nt).


Lethbridge_tRNApurification.png

Figure 4 - Successful tRNAPhe Purification. 12% 8M urea PAGE run for 45 mins at 300 V. All fractions were phenol chloroform extracted, ethanol precipitated and re-suspended in 30 µL of ddH2O. Lanes are as follows - 1- MS2 fraction 25 units of RNase H added; 2- tRNA fraction 25 units of RNase H added; 3- MS2 fraction 50 units of RNase H added; 4- tRNA fraction 50 units of RNase H added; 5- MS2 fraction 100 units of RNase H added; 6- tRNA fraction 100 units of RNase H added; 7- MS2 fraction 10 units of RNase H added; 8- tRNA elution 10 units of RNase H added; 9- tRNA standard (76 nt).


Sequence and Features


Assembly Compatibility:
  • 10
    COMPATIBLE WITH RFC[10]
  • 12
    COMPATIBLE WITH RFC[12]
  • 21
    COMPATIBLE WITH RFC[21]
  • 23
    COMPATIBLE WITH RFC[23]
  • 25
    COMPATIBLE WITH RFC[25]
  • 1000
    COMPATIBLE WITH RFC[1000]


[edit]
Categories
//collections/cell-free_tx-tl
Parameters
None