Part:BBa_K1412005

RBS (1.0) CheZ double terminators

This part consists of a CheZ coding region which is responsible for the dephosphorylation of CheY-P protein in E.coli chemotaxis system. This part does not pose any biological threat. With a promoter of you interest, this device can endow chemotaxis ability to.E.coli CL-1 whose CheZ gene is knocked out of genome. It has been reported that ΔCheZ strain has a higher frequency of direction change and thus resulting low chemotaxis ability with a narrower range of mobility. This part also has a RBS coding region whose efficiency is 1.0.

Biology

Chemotaxis in E.coli is well documented. These bacteria can perform two types of movement, tumbling and smooth swimming. The difference between the two is determined by flagellar movement. During tumbling movement, the flagella move clockwise. This is caused by the formation of a complex between CheY-P and FliM, one of the flagella-associated proteins. During smooth swimming, the flagella move counter-clockwise. CheY-P is not phosphorylated and therefore cannot associate with flagellar proteins, causing the flagella to rotate in the opposite direction. Smooth swimming is the movement performed by bacteria towards an attractant or away from a repellent. It is controlled by a number of chemotaxis proteins that make up a signalling pathway, please see the demonstration below for details.

Usage

1. We performed a swarming assay to characterize the motility of CheZ-deficient strain CL-1 and cells transformed with CheZ-expressing plasmid BBa_K1412001.

Our results clearly show that CheZ-deficient mutants show smaller diffusion, while they are rescued by our BBa_K1412001 plasmid.

2. We also performed a swarming assay to characterize the strength of RBS with CL-1 cells. Three strains of CL-1 are transformed with CheZ-expressing plasmid of different RBS efficiency (BBa_B0034:1.0; BBa_B0032:0.3; BBa_B0033:0.01).

Changing different RBS in the same circuit, we can characterize the efficiency of RBS, since the expression strength of CheZ is positively associated with the efficiency of RBS.

Experimental data

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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]

Reference

[1] [http://www.plosone.org/article/info%3Adoi%2F10.1371%2Fjournal.pone.0011915#pone-0011915-g006 Paungfoo-Lonhienne C et al. (2010) Turning the table: plants consume microbes as a source of nutrients. PLoS One 5(7): e11915].

[2] [http://pubs.acs.org/doi/abs/10.1021/bi00561a015 Chelsky D and Dahlquist FW (1980) Chemotaxis in Escherichia coli: association of protein components. Biochemistry 19: 4633–4639].