Difference between revisions of "Part:BBa K2253001"

Line 1: Line 1:
  
 
__NOTOC__
 
__NOTOC__
<partinfo>BBa_K2253001 short</partinfo>
+
<p>BBa_K2253001 short</p>
  
 
The P32 constitutive promoter is natively found in the genome of <i>Lactococcus lactis</i> <sup>[1]</sup>. Although the transcriptional efficiency of this promoter has been characterized and tested in <i>Lactococcus lactis</i> and other Gram-positive bacteria, its functionality in Gram-negative species such as <i>E. coli</i> has not been recorded in the literature. We have confirmed that <i>E. coli</i> transformed with a cassette plasmid containing the P32 promoter and E2-Crimson reporter is able to successfully express the E2-Crimson red fluorescent protein.  
 
The P32 constitutive promoter is natively found in the genome of <i>Lactococcus lactis</i> <sup>[1]</sup>. Although the transcriptional efficiency of this promoter has been characterized and tested in <i>Lactococcus lactis</i> and other Gram-positive bacteria, its functionality in Gram-negative species such as <i>E. coli</i> has not been recorded in the literature. We have confirmed that <i>E. coli</i> transformed with a cassette plasmid containing the P32 promoter and E2-Crimson reporter is able to successfully express the E2-Crimson red fluorescent protein.  

Revision as of 23:57, 31 October 2017


BBa_K2253001 short

The P32 constitutive promoter is natively found in the genome of Lactococcus lactis [1]. Although the transcriptional efficiency of this promoter has been characterized and tested in Lactococcus lactis and other Gram-positive bacteria, its functionality in Gram-negative species such as E. coli has not been recorded in the literature. We have confirmed that E. coli transformed with a cassette plasmid containing the P32 promoter and E2-Crimson reporter is able to successfully express the E2-Crimson red fluorescent protein.

Usage and Biology

As a PhytoBrick compatible part containing the proper overhangs, the P32 promoter can be assembled into a transcriptional unit via Golden Gate assembly method to upregulate expression of a gene of interest in E. coli as well as L. lactis. of a gene of interest in E. coli as well as L. lactis.

Experimental Design

To test if our Lactococcus lactis constitutive promoters function well within E. coli, we created a test cassette plasmid containing the E2-Crimson reporter gene (which encodes a red fluorescent protein) inserted downstream of the P32 promoter using BsaI Golden Gate assembly. To create this test cassette, we used the P32 promoter part plasmid, E2-Crimson part plasmid, an M13 terminator part plasmid, connector part plasmids, and the pYTK095 vector as the backbone. These part plasmids contained a distinct set of overhangs specified by the Lee/Dueber YTK Golden Gate Assembly standard [2].


Austin_UTexas--p8p32test1.jpg

Figure 1. Golden Gate assembly process of the P32 test cassette plasmid.


Top10 electrocompetent E. coli cells were transformed with the P32 cassette assembly and plated on LB + CAM plates. After one day of incubation at 37°C, there was growth of purple-blue colonies, which fluoresced red when placed under UV illumination. The observed red fluorescence phenotype was likely due to the P32 promoter successfully directing expression of the E2-Crimson reporter gene. From this result, we concluded that the P32 constitutive promoter is indeed functional within E. coli and can thus be used to overexpress genes of interest in E. coli as well as L. lactis.

T--Austin_UTexas--p32promotertransformationplate.jpg

Figure 2. P32 cassette plasmid transformation plate under normal light (left) and UV illumination (right).


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]


References

  1. Zhu, D. et al. Isolation of strong constitutive promoters from Lactococcus lactis subsp. Lactis N8. FEMS Microbiol Lett. 363(16): pii: fnv107 (2015).
  2. Lee, M. E. et al. A Highly Characterized Yeast Toolkit for Modular, Multipart Assembly. ACS Synth. Biol. 4(9): 975-86 (2015).