TY - JOUR A1 - Hochrein, Lena A1 - Machens, Fabian A1 - Messerschmidt, Katrin A1 - Müller-Röber, Bernd T1 - PhiReX: a programmable and red light-regulated protein expression switch for yeast JF - Nucleic acids research N2 - Highly regulated induction systems enabling dose-dependent and reversible fine-tuning of protein expression output are beneficial for engineering complex biosynthetic pathways. To address this, we developed PhiReX, a novel red/far-red light-regulated protein expression system for use in Saccharomyces cerevisiae. PhiReX is based on the combination of a customizable synTALE DNA-binding domain, the VP64 activation domain and the light-sensitive dimerization of the photoreceptor PhyB and its interacting partner PIF3 from Arabidopsis thaliana. Robust gene expression and high protein levels are achieved by combining genome integrated red light-sensing components with an episomal high-copy reporter construct. The gene of interest as well as the synTALE DNA-binding domain can be easily exchanged, allowing the flexible regulation of any desired gene by targeting endogenous or heterologous promoter regions. To allow low-cost induction of gene expression for industrial fermentation processes, we engineered yeast to endogenously produce the chromophore required for the effective dimerization of PhyB and PIF3. Time course experiments demonstrate high-level induction over a period of at least 48 h. Y1 - 2017 U6 - https://doi.org/10.1093/nar/gkx610 SN - 0305-1048 SN - 1362-4962 VL - 45 SP - 9193 EP - 9205 PB - Oxford Univ. Press CY - Oxford ER - TY - JOUR A1 - Hochrein, Lena A1 - Mitchell, Leslie A. A1 - Schulz, Karina A1 - Messerschmidt, Katrin A1 - Müller-Röber, Bernd T1 - L-SCRaMbLE as a tool for light-controlled Cre-mediated recombination in yeast JF - Nature Communications N2 - The synthetic yeast genome constructed by the International Synthetic Yeast Sc2.0 consortium adds thousands of loxPsym recombination sites to all 16 redesigned chromosomes, allowing the shuffling of Sc2.0 chromosome parts by the Cre-loxP recombination system thereby enabling genome evolution experiments. Here, we present L-SCRaMbLE, a lightcontrolled Cre recombinase for use in the yeast Saccharomyces cerevisiae. L-SCRaMbLE allows tight regulation of recombinase activity with up to 179-fold induction upon exposure to red light. The extent of recombination depends on induction time and concentration of the chromophore phycocyanobilin (PCB), which can be easily adjusted. The tool presented here provides improved recombination control over the previously reported estradiol-dependent SCRaMbLE induction system, mediating a larger variety of possible recombination events in SCRaMbLE-ing a reporter plasmid. Thereby, L-SCRaMbLE boosts the potential for further customization and provides a facile application for use in the S. cerevisiae genome reengineering project Sc2.0 or in other recombination-based systems. Y1 - 2018 U6 - https://doi.org/10.1038/s41467-017-02208-6 SN - 2041-1723 VL - 9 PB - Nature Publ. Group CY - London ER - TY - JOUR A1 - Messerschmidt, Katrin A1 - Hochrein, Lena A1 - Dehm, Daniel A1 - Schulz, Karina A1 - Mueller-Roeber, Bernd T1 - Characterizing seamless ligation cloning extract for synthetic biological applications JF - Analytical biochemistry : methods in the biological sciences N2 - Synthetic biology aims at designing and engineering organisms. The engineering process typically requires the establishment of suitable DNA constructs generated through fusion of multiple protein coding and regulatory sequences. Conventional cloning techniques, including those involving restriction enzymes and ligases, are often of limited scope, in particular when many DNA fragments must be joined or scar-free fusions are mandatory. Overlap-based-cloning methods have the potential to overcome such limitations. One such method uses seamless ligation cloning extract (SLiCE) prepared from Escherichia coli cells for straightforward and efficient in vitro fusion of DNA fragments. Here, we systematically characterized extracts prepared from the unmodified E. coli strain DH10B for SLiCE-mediated cloning and determined DNA sequence-associated parameters that affect cloning efficiency. Our data revealed the virtual absence of length restrictions for vector backbone (up to 13.5 kbp) and insert (90 bp to 1.6 kbp). Furthermore, differences in GC content in homology regions are easily tolerated and the deletion of unwanted vector sequences concomitant with targeted fragment insertion is straightforward. Thus, SLiCE represents a highly versatile DNA fusion method suitable for cloning projects in virtually all molecular. and synthetic biology projects. (C) 2016 Elsevier Inc. All rights reserved. KW - SLiCE KW - Seamless ligation cloning KW - Homologous recombination KW - Synthetic biology Y1 - 2016 U6 - https://doi.org/10.1016/j.ab.2016.05.029 SN - 0003-2697 SN - 1096-0309 VL - 509 SP - 24 EP - 32 PB - Elsevier CY - San Diego ER - TY - JOUR A1 - Hochrein, Lena A1 - Machens, Fabian A1 - Gremmels, Juergen A1 - Schulz, Karina A1 - Messerschmidt, Katrin A1 - Mueller-Roeber, Bernd T1 - AssemblX: a user-friendly toolkit for rapid and reliable multi-gene assemblies JF - Nucleic acids research N2 - The assembly of large DNA constructs coding for entire pathways poses a major challenge in the field of synthetic biology. Here, we present AssemblX, a novel, user-friendly and highly efficient multi-gene assembly strategy. The software-assisted AssemblX process allows even unexperienced users to rapidly design, build and test DNA constructs with currently up to 25 functional units, from 75 or more subunits. At the gene level, AssemblX uses scar-free, overlap-based and sequence-independent methods, allowing the unrestricted design of transcriptional units without laborious parts domestication. The assembly into multi-gene modules is enabled via a standardized, highly efficient, polymerase chain reaction-free and virtually sequence-independent scheme, which relies on rare cutting restriction enzymes and optimized adapter sequences. Selection and marker switching strategies render the whole process reliable, rapid and very effective. The assembly product can be easily transferred to any desired expression host, making AssemblX useful for researchers from various fields. Y1 - 2017 U6 - https://doi.org/10.1093/nar/gkx034 SN - 0305-1048 SN - 1362-4962 VL - 45 PB - Oxford Univ. Press CY - Oxford ER -