Coding

Part:BBa_K3039013

Designed by: Ceilidh Welsh   Group: iGEM19_Exeter   (2019-08-30)
Revision as of 11:06, 30 August 2019 by CeilidhWelsh (Talk | contribs)


SP_malE-MHETase S416A_F424N

Usage and Biology


The enzymes PETase and MHETase were first discovered in Ideonella sakaiensis in 2016 by a group of researchers in Japan. These enzymes were found to degrade polyethylene terephthalate (PET) into its monomers, terephthalic acid (TPA) and ethylene glycol (EG). PETase degrades PET into Mono-(2-hydroxyethyl)terephthalic acid (MHET), Bis(2-Hydroxyethyl) terephthalate (BHET) and TPA, the main product being MHET. MHET is further degraded by MHETase into TPA and EG. We are aiming to use mutants of these enzymes to degrade the microfibres that are coming off clothing during washing cycles. The enzymes would be secreted into a filter that captures the microfibres. This sequence is the Escherichia coli K12 (E. coli K12) codon optimized DNA of the S416A_F424N mutant MHETase with the malE signal peptide and a His tag attached. The malE signal peptide has been used in order to secrete the enzyme outside E.coli and the His tag was attached in order to more easily identify the enzymes.. The wild type MHETase doesn’t show BHET degrading activity. These mutation has been reported in past papers to give MHETase the ability to degrade BHET.




The native predicted signal peptide (Met1-Ala19) was removed from the WT MHETase sequence (Palm et al 2019) and replaced with a start codon (Met), however all mutations are numbered according to the full-length WT sequence. The 27 AA malE signal peptide, which allows for excretion of the enzyme via the Sec-dependent translocation pathway (Seo et al 2019) was added to the N-terminal followed by a 13 AA His-tag. The entire amino acid sequence was codon optimised for E. coli by IDT’s on-line Codon Optimisation tool ensuring that there were no forbidden restriction sites, BsaI or SapI, to allow for TypeIIS assembly. The iGEM TypeIIS prefix and suffix were added and DNA was synthesised by IDT as a double stranded g-block. TypeIIS assembly was used to clone the resulting CDS with the T7-promoter and B0015 terminator into a high-copy number, ampicillin vector, pX1900 (University of Exeter).


Sequence and Features


Assembly Compatibility:
  • 10
    COMPATIBLE WITH RFC[10]
  • 12
    COMPATIBLE WITH RFC[12]
  • 21
    INCOMPATIBLE WITH RFC[21]
    Illegal BamHI site found at 615
  • 23
    COMPATIBLE WITH RFC[23]
  • 25
    COMPATIBLE WITH RFC[25]
  • 1000
    COMPATIBLE WITH RFC[1000]


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Categories
Parameters
None