Team:Austin Texas

Read about our projects!

Photocage Project!

[Project Description Goes Here]

Kit Project!

Noncanonical amino acids (ncAAs) are an exciting new tool in the biological researchers toolbox. Incorporating ncAAs into proteins will allow scientists to create bacteria that can perform novel or new functions. The amberless E. coli used in this kit have had all the amber stop codons in its genome recoded and removed to allow the amber codon to be used for ncAAs. Unfortunately, these noncanonical amino acids are often difficult to incorporate into proteins due to a low fidelity of the synthetase/tRNA pair. Our project aims to create a kit that can measure the fidelity of the synthetase/tRNA pair and incorporation of several different noncanonical amino acids into fluorescent proteins. The kit is a simple two-plasmid system. The first plasmid contains an IPTG-inducible RFP, followed by a linker sequence containing a recoded amber stop codon (where the ncAA will be incorporated) and sfGFP. The other plasmid contains the synthetase/tRNA pair. When the RFP-linker-GFP protein is induced and exposed to the excitation wavelengths for RFP and GFP, the fluorescence of both parts of the fusion protein can be measured and compared. Depending on the relative intensities of the RFP and GFP fluorescent proteins, we can determine how efficient the synthetase/tRNA pairs are at incorporating the ncAA. We plan to equip researchers with a quick and easy “plug and play” system that contains easily interchangeable parts. Researchers will be able to insert any plasmid containing a new synthetase/tRNA pair into our pre-made cells to test the fidelity and incorporation of various ncAAs.

Caffeine Project!

The 2012 UT Austin iGEM team isolated and refactored a gene cluster from Pseudomonas putida CBB5 that codes for a demethylation enzyme pathway to convert caffeine to xanthine, then cloned the plasmid into a xanthine biosynthesis knockout strain to “addict” the strain to caffeine. The strain was growth-limited by the amount of xanthine produced by the pathway, and the team was able to measure the amount of methylxanthines in a common beverage, such as caffeine in coffee, based on the amount of growth of the strain supplemented with the beverage.

This year, our team seeks to better characterize the pathway and improve the measurement system. A beverage like coffee inherently contains various methylxanthines that can all feed into the enzyme pathway and allow growth. By creating a series of combinatorial knockout plasmids based on the refactored gene cluster, we should be able to more exactly measure amounts of methylxanthines specifically, as opposed to collectively as before, in a beverage. Additionally, by using standards, the plasmids will help to understand whether the pathway has a specific order, which is currently not defined.