title: Characterization of 582 natural and synthetic terminators and quantification of their design constraints.
abstract: Large genetic engineering projects require more cistrons and consequently more strong and reliable transcriptional terminators. We have measured the strengths of a library of terminators, including 227 that are annotated in Escherichia coli--90 of which we also tested in the reverse orientation--and 265 synthetic terminators. Within this library we found 39 strong terminators, yielding >50-fold reduction in downstream expression, that have sufficient sequence diversity to reduce homologous recombination when used together in a design. We used these data to determine how the terminator sequence contributes to its strength. The dominant parameters were incorporated into a biophysical model that considers the role of the hairpin in the displacement of the U-tract from the DNA. The availability of many terminators of varying strength, as well as an understanding of the sequence dependence of their properties, will extend their usability in the forward design of synthetic cistrons.
authors.affiliation: Department of Biological Engineering, Synthetic Biology Center, Massachusetts Institute of Technology, Cambridge, Massachusetts, USA.
authors.forename: Ying-Ja
authors.initials: YJ
authors.lastname: Chen
authors.forename: Peng
authors.initials: P
authors.lastname: Liu
authors.forename: Alec A K
authors.initials: AA
authors.lastname: Nielsen
authors.forename: Jennifer A N
authors.initials: JA
authors.lastname: Brophy
authors.forename: Kevin
authors.initials: K
authors.lastname: Clancy
authors.forename: Todd
authors.initials: T
authors.lastname: Peterson
authors.forename: Christopher A
authors.initials: CA
authors.lastname: Voigt
mesh_terms: D001483:Base Sequence; D004269:DNA, Bacterial / Q000235:genetics*; D004926:Escherichia coli / Q000235:genetics*; D008969:Molecular Sequence Data; D058615:Synthetic Biology / Q000379:methods*; D013728:Terminator Regions, Genetic / Q000235:genetics*
chemical_list: D004269:DNA, Bacterial