A Tale of Two Reductases: Extending the Bacteriochlorophyll Biosynthetic Pathway in E. coli

摘要: The creation of a synthetic microbe that can harvest energy from sunlight to drive its metabolic processes is an attractive approach the economically viable biosynthetic production target compounds. Our aim design and engineer genetically tractable non-photosynthetic produce light-harvesting molecules. Previously we created modular, multienzyme system for heterologous intermediates bacteriochlorophyll (BChl) pathway in E. coli. In this report extend include substrate promiscuous 8-vinyl reductase accept multiple BChl biosynthesis. We present informative comparative analysis homologues model photosynthetic organisms Rhodobacter sphaeroides Chlorobaculum tepidum. first purification enzymes leads their detailed biochemical biophysical characterization. data obtained reveal two reductases are promiscuous, capable reducing C8-vinyl group Mg protoporphyrin IX, IX methylester, divinyl protochlorophyllide. However, activity dependent upon presence chelated Mg2+ porphyrin ring, with no against non-Mg2+ observed. Additionally, CD analyses appear bind same different fashion. Furthermore, discover rates reaction both vitro, vivo as part our engineered system, results suitability only one offer insights into functionalities homologous reductases. This study also takes us step closer nonphotosynthetic harvesting biosynthesis molecules choice.