Team:IISER-Tirupati India/Contribution



New Parts:


In order to achieve robustness in the system, it is necessary to have a library of promoters with a wide range of transcription rates. One such library of synthetic promoters from Liu et al. (2018) consisted of 214 synthetic promoters with consensus sequence as shown below [1]:

Letter representation of SP backbone showing different regions.

Fig. 1 SP Backbone

All these promoters are constitutive hence can be used for general protein production. From this library we used SP126, SP146 and SP200 having relative activity with respect to P43 as follows:

Table 1. SP Promoters used


Sequence 5' → 3'

Relative activity wrt P43- GFP (%)

Standard deviation













P22 Operator Library:

P22 c2 repressor (BBa_K3889020, BBa_C0053) binds to the binding site (operator site) as a dimer. This inhibits the enzymes from transcribing the genes on whose promoter this operator site is fused. Hence this could be used with any promoter to form a repressible system. Different binding affinities of a repressor provide a variable system that can be used for different expression levels of the target, thereby enabling it in a variety of systems [2]. Optimization and tweaking of a system can be done by varying the operator sites as well.

Table 2. P22 binding sites and their Rel KD and KD

Part Name


Rel KD

K D (in M)

P22 binding site A



1.6 × 10−8

P22 binding site B



2.88 × 10-8

P22 binding site C



3.2 × 10−8

P22 binding site D



4.16 × 10−8

P22 binding site E



6.08 × 10−8

P22 binding site F



6.88 × 10−8

P22 binding site G



8.0 × 10−8

P22 binding site H



1.216 × 10−7

P22 binding site I



1.6 × 10−7

P22 binding site J



1.6 × 10−7

P22 binding site K



4.8 × 10−7

P22 binding site L



8.8 × 10−7

Histogram showing the different values of K<sub>D</sub> values of different parts on the y-axis, there is rel K<sub>D</sub> and on the x-axis there is part number.
Fig.2 - KD values of P22 binding site

Coding sequences:

SRTF1 or steroid responsive transcription factor 1 can negatively regulate any promoter activity if its binding site is fused with the gene's promoter. SRTF1 binds to its binding site(BBa_K3889030) as done in BBa_K3889150. Presence of progesterone causes unbinding of SRTF1 thereby releasing it from the DNA, inducing the target gene.Thus,progesterone acts as an inducer and can be used in a progesterone inducible system by other teams as well [3].


Terminator checking device (BBa_K3889140): In order to check terminator efficiency a simple reference circuit was used similar to what used by Gale et al. (2021) [4] as shown below:

Genetic Circuit of terminator check device.
Fig.3 - Terminator Check Device/Reference

Now, spacer can be replaced with any terminator to see the expression of sfGFP and mCherry.

Genetic circuit showing the terminator to be checked.
Fig.4 - Terminator to be checked

Formulae for terminator efficiency [4] :

\(TE_{Device} = \frac{mCherry_{0}}{sfGFP_{0}}\)


\(mCherry_{0} \rightarrow\) mCherry produced by device without terminator

\(sfGFP_{0} \rightarrow\) sfGFP produced by device without terminator

Using the device/reference without any changes, \(TE_{Device}\) can be calculated which gives the expression of \(mCherry\) in absence of a terminator.


\(mCherry \rightarrow\) mCherry produced by device with the terminator that needs to checked

\(sfGFP \rightarrow\) sfGFP produced by device with the terminator that needs to checked

Modifications in the old parts:

Table 3.

Old part 

New part


Modifications made




Removed Dual stop codons



P22 c2 repressor

Removed Sap1 Recognition Site, LVA tag and Barcodes



P2A Peptide Linker PTV

BsmBI recognition site removed for Golden Gate compatibility



YqcG toxin

Mutated Xho1, HindIII and Bsa1 sites to make assembly compatible part



YqcF antitoxin

Mutated BgIII site




Mutated Bsa1 and HindIII Sites



bovine pancreatic DNase 1

Mutated HindIII Site



mf-Lon protease

Mutated multiple RE sites




Mutated Kpn1 site and stop codon


  1. Liu, D., Mao, Z., Guo, J., Wei, L., Ma, H., Tang, Y., Chen, T., Wang, Z., & Zhao, X. (2018). Construction, Model-Based Analysis, and Characterization of a Promoter Library for Fine-Tuned Gene Expression in Bacillus subtilis. ACS Synthetic Biology, 7(7), 1785–1797. 
  2. Watkins, D., Hsiao, C., Woods, K. K., Koudelka, G. B., & Williams, L. D. (2008). P22 c2 Repressor− Operator Complex:  Mechanisms of Direct and Indirect Readout. Biochemistry, 47(8), 2325–2338.
  3. Baer, R. Cooper (2020). Discovery, characterization, and ligand specificity engineering of a novel bacterial transcription factor inducible by progesterone Boston University School of Medicine, 801 Massachusetts Avenue Suite 400 Boston, MA 02118 Retrieved from:
  4. Gale, G. A. R., Wang, B., & McCormick, A. J. (2021). Evaluation and Comparison of the Efficiency of Transcription Terminators in Different Cyanobacterial Species. Frontiers in Microbiology, 11. 

Gene Gala 

We held a Mini-Summer school in collaboration with the iGEM 2021 team of IISER Kolkata. It was a 5-day Mini-Summer School for Girl students studying in 12th Standards of the schools under the Directorate of Education, GNCT Delhi. As part of the summer school, the two teams together prepared a 5-days lesson plan, two quiz sessions, and a day-to-day handbook made for reference for the students. We would like to present these resources as a contribution to iGEM. 

Future iGEM teams can use them directly for conducting similar programs in their regions/countries to the relevant audiences giving proper attributions to both the contributing teams. These resources will be extremely useful for teams who are preparing for similar education events. Conducting classes for five days enriched with activities and quiz sessions can be a daunting task for teams. The lesson plan provided here was able to keep the students engaged throughout the five days and it was easy for the team members to present as well. These content handbooks, lesson plans, and quizzes will come in handy for future iGEM teams to prepare for such an event and take their public engagement to the next level

The content is relevant for introducing high school seniors to Synthetic Biology while giving them a holistic and application-based view of the biology courses taught at the high school level. 

Downloads Mini Summer School Resources

Gene Gala-Handbook

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  1. Gene Gala Quiz 1

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  2. Gene Gala Quiz 2

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  3. Gene Gala Quiz Answer Key

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Lesson plan - Gene Gala

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Class Material

Day 1

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  1. Day 2

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Day 3

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Day 4

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Note: It will be helpful if 2 people present the content, which will stop the lesson from becoming monotonous and keep students engaged.

The Handbook of Biotechnology Laws in India (Post Jamboree Addition)

We drafted a Handbook in collaboration with Team IISER Thiruvananthapuram on Biotechnology Laws in India. The book compiles relevant biotechnology laws in India and Multilateral legal agreements of which India is a part of. The biotechnology laws identified were categorised into Animal experimentation and Clinical trials, Export-Import Policies, and Environmental Safety. In addition, the book includes sections on Unattended problems and gaps in legal architecture and safety guidelines for iGEM Teams to follow.

Future iGEM Teams and researchers in biotechnology can use the book as a guide to go through the relevant biotechnology laws before commencing their project. The section on guidelines for iGEM Teams to follow will be particularly useful for future iGEM Teams when doing their project for ensuring safety and managing potential risks. We believe this is an important contribution to promoting responsible research and safety practices in the iGEM Community. The Handbook also serves as a useful resource for International Teams to compare, contrast and build similar resources for their country.

To read our Handbook, see The Handbook of Biotechnology Laws in India