title: Novel Utilization of Terminators in the Design of Biologically Adjustable Synthetic Filters.
abstract: Terminators, which signal the end of transcription processes, are typically placed behind the last coding sequence of an operon to prevent interference between transcript units in most biologically synthetic systems. Here, we seek to extend the usability of terminators in genetic system design by using terminators as regulatory genetic parts. Terminators with different impacts on their upstream and downstream genes are characterized in detail via dynamic modeling to predict the behavior of the overall genetic system. Some nonlinear effects of terminators observed in our terminator measurements potentially facilitate regulation of gene expression. Through dynamic modeling in silico, we find that such genetic systems may behave like genetic filters. In agreement with the simulations, we successfully implement genetic high-pass and bandpass filters in vivo, demonstrating the potential of using terminators as regulatory parts. The genetic bandpass filter in this work is implemented through the interdependence between genetic parts, in which the termination efficiency of a terminator varies with the strength of the upstream promoter. This design strategy for a bandpass filter requires fewer base pairs than the conventional strategy of concatenating high-pass and low-pass filters. Our results show that this novel utilization of terminators as regulatory parts may provide a new perspective for efficient design of genetic circuits. We believe that further exploration of the complicated dynamics of terminators is important in the development of synthetic biology.
authors.affiliation: Institute of Communications Engineering, National Tsing Hua University , Hsinchu 30013, Taiwan.
authors.forename: Mei-Ting
authors.initials: MT
authors.lastname: Lin
authors.affiliation: Department of Electrical Engineering, National Tsing Hua University , Hsinchu 30013, Taiwan.
authors.forename: Chun-Ying
authors.initials: CY
authors.lastname: Wang
authors.affiliation: Department of Biomedical Engineering, National Cheng Kung University , Tainan City 701, Taiwan.
authors.forename: Hui-Juan
authors.initials: HJ
authors.lastname: Xie
authors.affiliation: Institute of Molecular and Cellular Biology, National Taiwan University , Taipei 106, Taiwan.
authors.forename: Chantal Hoi Yin
authors.initials: CH
authors.lastname: Cheung
authors.affiliation: Institute of Molecular and Cellular Biology, National Taiwan University , Taipei 106, Taiwan.
authors.forename: Chiao-Hui
authors.initials: CH
authors.lastname: Hsieh
authors.affiliation: Institute of Molecular and Cellular Biology, National Taiwan University , Taipei 106, Taiwan.
authors.forename: Hsueh-Fen
authors.initials: HF
authors.lastname: Juan
authors.affiliation: Department of Electrical Engineering, National Tsing Hua University , Hsinchu 30013, Taiwan.
authors.forename: Bor-Sen
authors.initials: BS
authors.lastname: Chen
authors.affiliation: Institute of Communications Engineering, National Tsing Hua University , Hsinchu 30013, Taiwan.
authors.forename: Che
authors.initials: C
authors.lastname: Lin
mesh_terms: D004926:Escherichia coli / Q000235:genetics; D005809:Genes, Regulator / Q000235:genetics; D009876:Operon / Q000235:genetics; D011401:Promoter Regions, Genetic / Q000235:genetics; D058615:Synthetic Biology / Q000379:methods*; D013728:Terminator Regions, Genetic / Q000235:genetics*; D014158:Transcription, Genetic / Q000235:genetics
keywords: Escherichia coli; dynamic modeling; intrinsic terminator; synthetic biology; synthetic filter