Part:BBa_K1828999
nlmAB promoter
Description
The natural promoter found in Streptococcus mutans is regulated by the CSP concentration of the ability to stimulate the peptide. When no exogenous CSP is added, the expression strength is weak, and the addition of exogenous CSP can up-regulate the promoter.
Sequence and Features
- 10COMPATIBLE WITH RFC[10]
- 12COMPATIBLE WITH RFC[12]
- 21COMPATIBLE WITH RFC[21]
- 23COMPATIBLE WITH RFC[23]
- 25COMPATIBLE WITH RFC[25]
- 1000COMPATIBLE WITH RFC[1000]
HZAU-China 2020's contribution
(The following experimental data are from the literature, not the actual data made by the team)
We knew from the literature that ComDE two component system exists in gram-positive bacteria plays an important role in quorum sensing in Streptococcus mutans. After being effected by CSP (competence stimulate peptide) secreted by S.mutans, the cascade reaction will take place in ComDE two component system, phosphorylated ComE then act on the conservative sequence which is called DR sequence (direct repeat sequence) (Figure 1) [1],the process changes the conformation of the region of these specific promoters, and makes it easy for RNA polymerase to combine to the specific region, thus induce the expression of genes coding mutacin like comAB and comX [2].
Figure 1. Phosphorylated ComE in ComDE two component system can recognize and combine to the conservative sequences DR (direct repeat sequences) in the promoters of mutacin-coding genes.
It has been demonstrated in the literature that ComDE two component system has the ability to activate nlmAB promoter in Streptococcus. mutans by using β-galactosidase as reporter (Figure 2) [2].So we used PnlmAB (nlmAB promoter) as an important part. Our study aims to figure out the sensitivity to phohsphorylated ComE of PnlmAB by literature.
Figure 2. The experiment was conducted in S.mutans. β-galactosidase-coding gene was connected to nlmAB promoter as the reporter gene, there was a great increasing tendency of expressed β-galactosidase with the increasing amount of added CSP.
References
[1]Merritt J , Qi F . The mutacins of Streptococcus mutans: regulation and ecology[J]. Molecular Oral Microbiology, 2012, 27(2):57-69.
[2]Ploeg V D , J. R . Regulation of bacteriocin production in Streptococcus mutans by the quorum-sensing system required for development of genetic competence.[J]. Journal of Bacteriology, 2005, 187(12):3980.
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