Translational_Unit

Part:BBa_K4028008

Designed by: Ke ZHU   Group: iGEM21_Shanghai_Metro   (2021-10-12)

lac pro-tke2-tet pro-ike2


Assembly Compatibility:
  • 10
    COMPATIBLE WITH RFC[10]
  • 12
    COMPATIBLE WITH RFC[12]
  • 21
    COMPATIBLE WITH RFC[21]
  • 23
    COMPATIBLE WITH RFC[23]
  • 25
    INCOMPATIBLE WITH RFC[25]
    Illegal NgoMIV site found at 200
    Illegal NgoMIV site found at 212
    Illegal NgoMIV site found at 629
    Illegal NgoMIV site found at 671
    Illegal NgoMIV site found at 2920
    Illegal AgeI site found at 2550
  • 1000
    COMPATIBLE WITH RFC[1000]

Profile

Name: lac pro-tke2-tet pro-ike2

Base Pairs: 4746 bp

Origin: Escherichia coli, Pseudomonas putida KT2440, synthetic

Properties: Gene technology for protecting patented bacterial strains

Usage and Biology

A wide range of Gram-negative bacteria have been shown to have antibacterial T6SSs, including opportunistic pathogens such as Pseudomonas aeruginosa,[4] obligate commensal species that inhabit the human gut (Bacteroides spp.),[5] and plant-associated bacteria such as Agrobacterium tumefaciens.[6] Under natural conditions, bacterial cells encoding T6SS transport effect factors with cytotoxic or antibacterial effects (amidase, glycoside hydrolyase, lipase, etc.) to recipient cells through physical contact, thus inhibiting the growth of recipient cells. Meanwhile, the bacteria encoding T6SS can translate and produce corresponding immune protein to counteract the damage caused by toxic effector factors.[1,2,3]

Figure1. Principle diagram of T6SS.

Construct design

With this idea coming from the T6SS, we designed to express the effector components of T6SS in industrial strains by inserting the gene segment tke2-ike2 to induce the controlled expression of the corresponding immune proteins. The normal growth of industrial microorganisms can be ensured only by adding certain components (tetracycline) in the fermentation broth, so as to achieve the purpose of the experiment.

Figure2. The gene design of TetR promoter-ike2-lac promoter-tke2.
Figure3. Schematic map of T6SS effector and immune expression plasmids.

The profiles of every basic part are as follows:

BBa_K4028000

Name: tke2

Base Pairs: 4158 bp

Origin: Pseudomonas putida KT2440, genome

Properties: Anti-bacterial effector in type VI secretion system

Usage and Biology

BBa_K4028000 is a coding sequence of tke2 from Pseudomonas putida KT2440. Tke2, known as a toxic Rhs-type effector, is an effect factor in type VI secretion system (T6SS).

BBa_K4028001

Name: ike2

Base Pairs: 447bp

Origin: Pseudomonas putida KT2440, genome

Properties: Immunity effector in type VI secretion system

Usage and Biology

BBa_K4028001 is a coding sequence of ike2, an immunity protein in Pseudomonas putida KT2440. Ike2 is used for protecting bacteria from type VI secretion system (T6SS). (T6SS).

BBa_K4028004

Name: lac promoter

Base Pairs: 55bp

Origin: Escherichia coli, synthetic

Properties: Constitutive promoter used for protein expression

Usage and Biology

This is a medium-strength Plac promoter. Placed before a gene, it promotes its expression. Plac is repressed by LacI. This promoter can be used for in vivo reporter systems; its medium strength is interesting for reporter genes that have a long half-life or that are not well supported by the cell.

BBa_K4028005

Name: tet promoter Base Pairs: 56bp

Origin: Escherichia coli, synthetic

Properties: Inducible promoter regulated by tetracycline

Usage and Biology

This is the naturally-occuring version of the TetR class B promoter. Note that this will promote bidirectionally. (pR1 and pR2 will promote in the forward direction; pA will promote in the reverse direction.) The three transcription start sites are not labeled, but can be found from the reference.

References

1. Bingle, l.E.H. et al. (2008). Type VI secretion: a beginner’s guide. Current opinion in microbiology. 11:3-8.

2. Silverman, J. M. et al. (2012). Structure and regulation of the type VI secretion system. 66:453-472.

3. Hernandez, R. E. et al. (2020). Type VI secretion system effector protein: Effective weapons for bacterial competitiveness. Cellular microbiology. 22:e13241.

4. Hood RD, . et al (January 2010). "A type VI secretion system ofPseudomonas aeruginosa targets a toxin to bacteria". Cell Host & Microbe. 7 (1): 25–37. doi:10.1016/j.chom.2009.12.007. PMC 2831478. PMID 20114026.

5. Russell AB, . et al (August 2014). "A type VI secretion-related pathway in Bacteroidetes mediates interbacterial antagonism". Cell Host & Microbe. 16 (2): 227–236. doi:10.1016/j.chom.2014.07.007. PMC 4136423. PMID 25070807.

6. Ma LS, . et al (July 2014). "Agrobacterium tumefaciens deploys a superfamily of type VI secretion DNase effectors as weapons for interbacterial competition in planta". Cell Host & Microbe. 16 (1): 94–104. doi:10.1016/j.chom.2014.06.002. PMC 4096383. PMID 24981331.

[edit]
Categories
Parameters
None