MotA and B0032 RBS under J23103 promoter
MotA with B0032 RBS under J23103 promoter.
Usage and Biology
We inserted the BBa_B0032 RBS – motA biobrick into the BBa_J61002 vector containing a variety of different promoters from the parts distribution:
BBa_J23106 (½ the strength of J23100)
BBa_J23116 (¼ the strength of J23100)
BBa_J23103 (very weak promoter)
BBa_J23112 (weakest promoter we could find in the registry, barely any expression)
(Strength measured with RFP: Part BBa_J23100)
These were checked by DNA sequencing and all found to have the expected sequence.
We then used swarm assays (semi-solid agar motility test) to investigate whether these plasmids would rescue swimming of a motA mutant. DS941 ΔmotA (with motA deleted) was transformed with pSB1C3 motA (no promoter), motA transcribed from the four different weaker promoters in BBa_J61002, and also motA with the strong J23100 promoter with the mutated ribosome binding site. The results of the swarm assays are shown in Figure 1. DS941 ΔmotA did not swim at all, as expected for this mutant knocked out for the MotA motor protein. None of the plasmids containing just motA restored swimming to the mutant to any significant extent.
Interestingly, however, composite biobricks containing motA and motB did restore swimming to our motA deletion mutant. See BBa_K1463700 for more details.
Fig. 4: Swarm assay. 5µ drop of overnight culture was added on a soft-agar plate and left incubated overnight at 37°C. Different strength promoters used this time.
Fig. 5: DS941 ΔmotA E. coli carrying plasmids with the indicated biobricks were tested for mobility on swarm plates. Growth diameter of swarm assay grown for 16 hours at 37 degrees C. Non knock-out strain used as a control.
More information on the biobrick and usage:
Sequence and Features
- 10COMPATIBLE WITH RFC
- 12Illegal NheI site found at 7
Illegal NheI site found at 30
- 21Illegal BglII site found at 385
- 23COMPATIBLE WITH RFC
- 25Illegal AgeI site found at 123
- 1000Illegal SapI.rc site found at 891