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Biology subjects

Lee, H. H.

Publications and source records attributed to Lee, H. H..

3 recordsLinked to original sources

Enzymatic DNA synthesis for digital information storage

DNA is an emerging storage medium for digital data but its adoption is hampered by limitations of phosphoramidite chemistry, which was developed for single-base accuracy required for biological functionality. Here, we establish a de novo enzymatic DNA synthesis strategy designed from the bottom-up for information storage. We harness a template-independent DNA polymerase for controlled synthesis of sequences with user-defined information content. We demonstrate retrieval of 144-bits, including addressing, from perfectly synthesized DNA strands using batch-processed Illumina and real-time Oxford Nanopore sequencing. We then develop a codec for data retrieval from populations of diverse but imperfectly synthesized DNA strands, each with a ~30% error tolerance. With this codec, we experimentally validate a kilobyte-scale design which stores 1 bit per nucleotide. Simulations of the codec support reliable and robust storage of information for large-scale systems. This work paves the way for alternative synthesis and sequencing strategies to advance information storage in DNA.

synthetic biology

Establishing a cell-free Vibrio natriegens expression system

The fast growing bacterium Vibrio natriegens is an emerging microbial host for biotechnology. Harnessing its productive cellular components may offer a compelling platform for rapid protein production and prototyping of metabolic pathways or genetic circuits. Here, we report the development of a V. natriegens cell-free expression system. We devised a simplified crude extract preparation protocol and achieved >260 g/mL of super-folder GFP in a small-scale batch reaction after three hours. Culturing conditions, including growth media and cell density, significantly affect translation kinetics and protein yield of extracts. We observed maximal protein yield at incubation temperatures of 26{degrees}C or 30{degrees}C, and show improved yield by tuning ions crucial for ribosomal stability. This work establishes an initial V. natriegens cell-free expression system, enables probing of V. natriegens biology, and will serve as a platform to accelerate metabolic engineering and synthetic biology applications.

synthetic biology

Recombineering in Vibrio natriegens

Here, we show that {lambda}-Red homologs found in the Vibrio-associated SXT mobile element potentiate allelic exchange in V. natriegens by 10,000-fold. Specifically, we show SXT-Beta (s065), SXT-Exo (s066), and {lambda}-Gam proteins are sufficient to enable recombination of single- and double-stranded DNA with episomal and genomic loci. We characterize and optimize episomal oligonucleotide-mediated recombineering and demonstrate recombineering at genomic loci. We further show targeted genomic deletion of the extracellular nuclease gene dns using a double-stranded DNA cassette. Continued development of this recombination technology will advance high-throughput and large-scale genetic engineering efforts to domesticate V. natriegens and to investigate its rapid growth rate.

synthetic biology