Coding

Part:BBa_K3746003

Designed by: Cheung Chi Ming   Group: iGEM21_Hong_Kong_JSS   (2021-10-17)

FDR-A(MSMEG5998)-6His

Description

This is a part design for the Phase I project (2021 iGEM) of Team Hong Kong JSS.

This basic part is the coding sequence of F420H2-dependent reductase (FDR) gene from bacterial species - Mycobacterium smegmatis, which was reported to have a high activity in degradation of aflatoxin B1 (AFB1).

FDR is a family of enzymes produced by bacterial species that catalyze the reduction of aflatoxin and lead to their spontaneous degradation and produce a non-toxic product. [1]

This enzyme can be found in bacterial strains such as Mycobacterium sp., Arthrobacter sp., and Pseudomonas sp.. The native function of the enzymes in these organisms is for methanogenesis [2], antibiotic resistance [3], and other redox-related metabolic activities. Nevertheless, it was believed that FDR’s native functions do not involve aflatoxin degradation since the above bacterial species seldom exist near any source of aflatoxin. Thus, it was a novel finding that FDRs are involved in the degradation of aflatoxin and there was considerable interest in the study of FDRs properties recently. [1]


Usage and Biology

In our project, we aim to investigate the AFB-1 degrading activity of FDR-A.

Aflatoxin (AF) is a family of carcinogenic toxins produced by Aspergillus sp.. According to the World Health Organization (WHO), 25% of food crops are destroyed due to aflatoxin contamination each year. About 5 billion people are at risk of chronic AF exposure and more than 80% of them will develop AF-related diseases such as hepatocellular carcinoma and liver failure. [4] Among all AF, aflatoxin B1 (AFB1) is considered the most potent and chronic. [5]

Among all species reviewed, Mycobacterium smegmatis was found to have the FDRs with the highest activity in AFB-1 degradation [6].

And from all the loci of the two FDR families (FDR-A and FDR-B) in M. smegmatis, FDR-A at locus MSMEG_5998 was found to have the highest enzymatic activity in degrading AFB1, AFB2, and AFG1. [1]

Che-Hsing Li, et al. (2019) had demonstrated that purified FDR-A from E. coli is able to retain its enzymatic activity in degrading AFB1 and iGEM 2017 Team CSMU_NCHU_Taiwan had demonstrated that FDR-A secreted by yeast is able to degrade AFB1 (BBa_K2382001). Therefore, we hypothesize that FDR-A would also show the high efficiency of AFB1 degradation in our project setting.

Fig. 1 Table showing FDR-A MSMEG_5998 had the highest efficiency in degrading AFB1. Table adopted from Taylor, M. C., et al. (2010)[1]


Moreover, literature showed that adding co-factors F420H2 can enhance the enzymatic activity of the FDR-A, so in our detoxifying spray, we planned to add the F420H2 cofactor with anti-oxidants into the buffer and thus increasing the efficiency of AFB1 degradation in our product.


This coding sequence is planned to be used in our composite parts for tvLac enzyme expression (BBa_K3746010), (BBa_K3746011), and (BBa_K3746012).

Note that a C-terminal 6-His Tag (CATCATCATCATCATCAT) was added to this part. For the secretory constructs, (BBa_K3746011) and (BBa_K3746012), the start codon is removed due to the addition of N-terminal signal peptide sequences.


Reference

[1] Taylor, M. C., Jackson, C. J., Tattersall, D. B., French, N., Peat, T. S., Newman, J., Briggs, L. J., Lapalikar, G. V., Campbell, P. M., Scott, C., Russell, R. J., & Oakeshott, J. G. (2010). Identification and characterization of two families of F420H2-dependent reductases from mycobacteria that catalyse aflatoxin degradation. Molecular Microbiology, 78(3), 561–575. https://doi.org/10.1111/j.1365-2958.2010.07356.x

[2] Graham, D.E., and White, R.H. (2002) Elucidation of methanogenic coenzyme biosyntheses: from spectroscopy to genomics. Nat Prod Rep 19: 133–147.

[3] Hasan, M.R., Rahman, M., Jaques, S., Purwantini, E., and Daniels, L. (2010) Glucose-6-phosphate accumulation in mycobacteria: implications for a novel F420-dependent anti-oxidant defense system. J Biol Chem 285: 19135– 19144.

[4] Organization WH. aflatoxin. Manuf Comput Solut. 2000;6(8):20-3

[5] Okwara, P. C., Afolabi, I. S., & Ahuekwe, E. F. (2021). Application of laccase in aflatoxin B1 degradation: A Review. IOP Conference Series: Materials Science and Engineering, 1107(1), 012178. https://doi.org/10.1088/1757-899x/1107/1/012178

[6] Verheecke, C., Liboz, T., & Mathieu, F. (2016). Microbial degradation of aflatoxin B1: Current status and future advances. International Journal of Food Microbiology, 237, 1–9. https://doi.org/10.1016/j.ijfoodmicro.2016.07.028


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
    INCOMPATIBLE WITH RFC[25]
    Illegal AgeI site found at 61
  • 1000
    COMPATIBLE WITH RFC[1000]
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Categories
Parameters
None