Copenhagen Plant Science Center, Center for Synthetic Biology 'bioSYNergy', Department of Plant and Environmental Sciences, University of Copenhagen, Thorvaldsensvej 40, 1871, Frederiksberg C, Denmark.
Photosynth Res. 2017 Dec;134(3):329-342. doi: 10.1007/s11120-017-0364-0. Epub 2017 Mar 11.
Plants, cyanobacteria, and algae generate a surplus of redox power through photosynthesis, which makes them attractive for biotechnological exploitations. While central metabolism consumes most of the energy, pathways introduced through metabolic engineering can also tap into this source of reducing power. Recent work on the metabolic engineering of photosynthetic organisms has shown that the electron carriers such as ferredoxin and flavodoxin can be used to couple heterologous enzymes to photosynthetic reducing power. Because these proteins have a plethora of interaction partners and rely on electrostatically steered complex formation, they form productive electron transfer complexes with non-native enzymes. A handful of examples demonstrate channeling of photosynthetic electrons to drive the activity of heterologous enzymes, and these focus mainly on hydrogenases and cytochrome P450s. However, competition from native pathways and inefficient electron transfer rates present major obstacles, which limit the productivity of heterologous reactions coupled to photosynthesis. We discuss specific approaches to address these bottlenecks and ensure high productivity of such enzymes in a photosynthetic context.
植物、蓝藻和藻类通过光合作用产生过剩的氧化还原能力，这使得它们成为生物技术开发的有吸引力的目标。虽然中心代谢消耗了大部分能量，但通过代谢工程引入的途径也可以利用这种还原能力的来源。最近关于光合生物的代谢工程的研究表明，电子载体如铁氧还蛋白和黄素氧还蛋白可用于将异源酶与光合还原能力偶联。由于这些蛋白质有大量的相互作用伙伴，并依赖于静电导向的复杂形成，它们与非天然酶形成有生产力的电子转移复合物。少数例子证明了光合电子的通道化可驱动异源酶的活性，这些主要集中在氢化酶和细胞色素 P450 上。然而，来自天然途径的竞争和低效的电子转移速率是主要障碍，限制了与光合作用偶联的异源反应的生产力。我们讨论了特定的方法来解决这些瓶颈问题，并确保在光合环境中此类酶的高生产力。
