Team:Virginia/Project

The Projects

Translating or otherwise implementing a metabolic pathway poses many problems. A major one is the need to tune the relative expression levels of the genes involved in the pathway. The goal is usually to optimize the flux of the intermediates involved. There are many levels at which regulation of expression can occur. Transcriptional, translational and post-translational regulation all exist in natural biological systems. Synthetic biologists have been working on gaining control of these mechanisms at each level to have better control of the novel systems they are designing. In transcriptional regulation a major approach for synthetic biology has been promoter engineering. Modifying natural promoters has yielded a library of promoters of varying strengths which can be used to tweak the transcription rate of genes of interest. However this approach is limited in that each gene that one hopes to affect needs to be placed under the control of its own promoter.

The 2008 team at the University of Virginia will be pursuing another approach to the problem of transcriptional regulation by trying to create a Genetic Attenuator. Terminators are not 100% efficient. When a polymerase working its way down a DNA strand runs into a terminator not all of them are kicked off the strand, some of them keep going. By changing the structure of the terminator we hope to create Genetic Attenuators of varying strengths which could be placed between genes to achieve any desired ratio of transcription.

As the world’s fossil fuel supply starts to decline, new methods of producing fossil-fuel derived products need to be established. Plastics are a major category of fossil-fuel derivatives that make modern life possible. Looking for a solution in the biological realm is an obvious start to this problem as “plastic” is a general term that encompasses “a wide range of synthetic or semisynthetic polymerization products.” Many examples of polymerization products can be found in nature. Among the pathways producing these products is the PHA synthesis pathway found in R. eutropha. This pathway has recently been sequenced allowing the tools of synthetic biology to be applied to translating and optimizing it in E. coli. This is a crucial step towards making this pathway industrially useful as E. coli are a standard chassis used to harness nature’s synthesis capabilities.