FliC with RBS
FliC encodes the major flagellar protein of E. coli and is thus fundamental to motility.
See Fig 1C for motility swarm assay results showing the function of this biobrick. In a fliC knockout strain, this biobrick alone was not enough to restore swimming. A promoter is necessary to drive fliC expression. When used in conjunction with various promoters (J23106 and J23116) and B0032 ribosome binding site, this biobrick was shown to restore swimming in fliC knockout strains (See Figures 1 & 2).
Flic Motility Swarm Assay
Test from Glasgow team 2014
Figure 1: FliC Swarm Motility Assays.
(A) DS941, (B) DS941 ΔfliC,
(C) DS941 ΔfliC + pSB1C3 fliC (no promoter), (D) DS941 ΔfliC + J23100 (mutant promoter) fliC,
(E) DS941 ΔfliC + J23116-fliC(1), (F) DS941 ΔfliC + J23116-fliC(2),
(G) DS941 ΔfliC + J23106-fliC(1), (H) DS941 ΔfliC + J23106-fliC(2)
Figure 2 - FliC Motility Histogram The promoters indicated in the histogram were used to drive the fliC biobrick K1463600 with the RBS B0034. Plasmids containing these constructs were used to complement a chromosomal fliC mutation. The diameter of swimming in a 16 hour swarm assay at 37 degrees is shown. The error bars indicate the range or results obtained in two repeats of the experiment. The strong J23100 promoter in this result contained a mutation rendering it inactive see K1463604.
For more information on the biobrick and methods used go to http://2014.igem.org/wiki/index.php?title=Team:Glasgow/Project/Mobility_Proteins#fliC
Sequence and Features
- 10COMPATIBLE WITH RFC
- 12COMPATIBLE WITH RFC
- 21Illegal BamHI site found at 1242
- 23COMPATIBLE WITH RFC
- 25Illegal AgeI site found at 319
Illegal AgeI site found at 727
- 1000COMPATIBLE WITH RFC
Improovement by Aix Marseille Team 2016 BBa_K1951008
This biobrick has been improoved from the previous one designed by Glasgow 2014 team. Please find the link of this biobrick below : BBa_K1951008
Proof the FliC protein production
We investigate if the FliC protein was well produced by our biobrick.
To make it, we did a SDS page and comassie blue. From an over night starter, cells have been growth from Abs(600nm)=0.2 until Abs(600nm)=0.6. Then 1uDO has been sampled and centrifuged at 5000g during 5min. After removal of the supernatant, cells were resuspended in 50µL SDS-PAGE sample buffer (Morris formulation). Mix has been charged on a polyacrylamide gel and migrated during 50min at 180V. Revelation was done using comassie blue.
The FliC size we were looking for was 51,3kDA.
Proof of swimming recovery
Here, we had a look if the protein produced by our biobrick was well traducted et abled to recover swing in a FliC deficient strain.
- To test it, we made a fliC mutant of E.coli W3110 strain by transduction using phage P1 (Transduction protocol)).
- fliC mutant W3110 has been complemented by our biobrick Bba_K1951008. On the following figure, we investigated if the complemented fliC mutant recovered swimming after complementation. To do this, we did a swimming test using soft gelose.
Result : WT W3110 strain was well swimming after 3 hours incubation at 37°C. However, the FliC mutant motility was absent whereas fliC mutant complemented recover the swimming ability, making a proof that our biobrick is produced a fonctionnal flagellin protein. Moreover, the circle was more intense in the complemented strain than in the wild type showing that more bacteria were able to swim.
Complementation by transformation of the W3110 mutant recovered the swimming capacity showing the integrity of the flagellin produced by Bba_K1951008.
Flagellum features by electronic microscopy
This step aims to observe the good assembly of the flagellin protein
We analysed the fliC mutant made by transduction as describe before complemented by BbaK1951008 using electronic microscopy with negative filter. This tools allowed us to observe the flagellum integrity recovered and to obtain image of our work. Image shows the presence of big and numerous flagellums in the complemented mutant while no any flagellum has been observed in the fliC mutant and less in the WT strain.
Improvement of the biobrick K1463601
This biobrick has been improved from a previous one designed by Glasgow 2014 team. Please find the link of this biobrick below : K1463601
Instead of Bba_J23106 and Bba_J23116, we used strong promoter, strong RBS combination for high expression levels of the flagellin. By the combination of Bba_K880005 and Bba_K1951005, we made a high flagellin expression vector able to highly recover swimming and even surexpress this pattern.