Team:Virginia

Transcription attenuation for metabolic control by engineering intrinsic terminators

A main challenge in constructing synthetic biological systems is the inability to precisely regulate gene expression using artificial means. Tightly-regulated control of any given set of related transcriptional, translational and posttranslational events will likely require a combination of powerful strategies. Therefore, the 2008 Virginia iGEM team is developing a library of transcriptional terminators intentionally redesigned to be functionally inefficient. Well-characterized, standardized terminators of various efficiencies should allow finely-tuned transcription attenuation and represents yet another step toward global biological control. This work complements other gene expression control methods that focus on initiation of transcription. The desired result is quantitative control of transcript levels, which is often necessary to balance flux through a synthetic metabolic pathway. To demonstrate its potential for real-world application, the team is planning to employ this approach to control the expression of a heterologous pathway in E. coli for the biosynthesis of polyhydroxybutyrate (PHB), a biodegradable polyester plastic.