Team:Acton-BoxboroughRHS/Research

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Welcome to the ABRHS iGEM team

ABRHS


Research

Pre-Research

E. Coli vs. Yeast

E.coli can live in a higher range of pH and should be easier to engineer, but may be less productive. Yeast will most likely be more be more productive in protein production in the long run but is otherwise inferior to the use of E. coli, so our decision is to use the latter. Also, we used a k12 strain of E. coli from Carolina Labs and a highly-competent strain of E. coli from New England BioLabs.

DNA Sequences

We need an open reading frame (orf) a ribosome binding site (rbs), a promoter, at least 3-5 enzymes:(pepsin, salivary amylase, trypsin, chymotripsin, and pancreatic amylase), and a terminator, to create a fully functional plasmid to digest the coffee beans.





This image shows the template for a typical plasmid requirement





Parts

The Promoter

A promoter is a DNA sequence that tends to recruit transcriptional machinery and lead to transcription of the downstream DNA sequence.



The Ribosome Binding Site

A ribosome binding site (RBS) is an RNA sequence found in mRNA to which ribosomes can bind and initiate translation.



The Open Reading Frames

.Protein domains are portions of proteins cloned in frame with other proteins domains to make up a protein coding sequence. Some protein domains might change the protein's location, alter its degradation rate, target the protein for cleavage, or enable it to be readily purified.



The Terminator

The Terminator is the 'last' region of the plasmid, where RNA polymerase stops transcription. There are two main types of terminators in prokaryotes, rho-dependent terminators, and rho-independent terminators. Rho-dependent termination bases its function on the Rho protein, which causes the RNA polymerase to fall disassociate form the plasmid.

Rho-independent termination does not use Rho to disassociate the RNA polymerase, but instead stops by the DNA sequence, here's how it works. The DNA sequence contains a two regions that are rich in cytosine and guanine. When this is transcribed, those regions on the RNA form hydrogen bonds to itself: effectively forming a 'loop' which disassociates the DNA polymerase from the DNA.

Within the category of rho-independent terminators, are terminators that stop transcription on the forward strand in forward direction (forward terminators), on both strands and directions (bi-directional terminators), and on the reverse strand and direction only (reverse terminators).

One specific part that seems promising is the rho-independent, forward terminator BBa_B1006, which has a 99 per cent success rate of terminating the transcription, the highest efficiency of all the terminators.



The Backbone

A plasmid is a circular, double-stranded DNA molecules typically containing a few thousand base pairs that replicate within the cell independently of the chromosomal DNA. A plasmid backbone is defined as the plasmid sequence beginning with the BioBrick suffix, including the replication origin and antibiotic resistance marker, and ending with the BioBrick prefix.





Anticipated Parts

Pepsin

This gene will help digest protein in the coffee bean. We need to find a pepsin gene more similar to the Paradoxurus hermaphroditus (Asian Palm Civet), because there are many different variations. Secretion: lysis with acid: we do not have the acid proof backbone in our plate.

Trypsin

New Updates!