Development of Novel Riboswitches for Synthetic Biology in the Green Alga Chlamydomonas

• Published in: ACS synthetic biology Vol. 9; no. 6; pp. 1406 - 1417
• Main Authors: Mehrshahi, Payam, Nguyen, Ginnie Trinh D T, Gorchs Rovira, Aleix, Sayer, Andrew, Llavero-Pasquina, Marcel, Lim Huei Sin, Michelle, Medcalf, Elliot J, Mendoza-Ochoa, Gonzalo I, Scaife, Mark A, Smith, Alison G
• Format: Journal Article
• Language: English
• Published: United States American Chemical Society 19.06.2020
• Subjects: 5' Untranslated Regions; Algal Proteins - genetics; Algal Proteins - metabolism; Aptamers, Nucleotide - genetics; Aptamers, Nucleotide - metabolism; Chlamydomonas - metabolism; Gene Expression; Metabolic Engineering - methods; Mutagenesis; Riboswitch - genetics; Thiamine Pyrophosphate - metabolism; Ultraviolet Rays; riboswitch; microalgae; synthetic biology; diterpenoid; metabolic engineering; Chlamydomonas
• ISSN: 2161-5063; 2161-5063
• DOI: 10.1021/acssynbio.0c00082

Riboswitches are RNA regulatory elements that bind specific ligands to control gene expression. Because of their modular composition, where a ligand-sensing aptamer domain is combined with an expression platform, riboswitches offer unique tools for synthetic biology applications. Here we took a mutational approach to determine functionally important nucleotide residues in the thiamine pyrophosphate (TPP) riboswitch in the THI4 gene of the model alga , allowing us to carry out aptamer swap using THIC aptamers from and . These chimeric riboswitches displayed a distinct specificity and dynamic range of responses to different ligands. Our studies demonstrate ease of assembly as 5'UTR DNA parts, predictability of output, and utility for controlled production of a high-value compound in . The simplicity of riboswitch incorporation in current design platforms will facilitate the generation of genetic circuits to advance synthetic biology and metabolic engineering of microalgae.