当前位置: X-MOL 学术Plant J. › 论文详情
Our official English website, www.x-mol.net, welcomes your feedback! (Note: you will need to create a separate account there.)
Reconstitution of oxaloacetate metabolism in the tricarboxylic acid cycle in Synechocystis sp. PCC 6803: discovery of important factors that directly affect the conversion of oxaloacetate
The Plant Journal ( IF 7.2 ) Pub Date : 2020-12-06 , DOI: 10.1111/tpj.15120
Shoki Ito 1 , Takumi Hakamada 1 , Tatsumi Ogino 1 , Takashi Osanai 1
Affiliation  

The tricarboxylic acid (TCA) cycle is one of the most important metabolic pathways in nature. Oxygenic photoautotrophic bacteria, cyanobacteria, have an unusual TCA cycle. The TCA cycle in cyanobacteria contains two unique enzymes that are not part of the TCA cycle in other organisms. In recent years, sustainable metabolite production from carbon dioxide using cyanobacteria has been looked at as a means to reduce the environmental burden of this gas. Among cyanobacteria, the unicellular cyanobacterium Synechocystis sp. PCC 6803 (Synechocystis 6803) is an optimal host for sustainable metabolite production. Recently, metabolite production using the TCA cycle in Synechocystis 6803 has been carried out. Previous studies revealed that the branch point of the oxidative and reductive TCA cycles, oxaloacetate metabolism, plays a key role in metabolite production. However, the biochemical mechanisms regulating oxaloacetate metabolism in Synechocystis 6803 are poorly understood. Concentrations of oxaloacetate in Synechocystis 6803 are extremely low, such that in vivo analysis of oxaloacetate metabolism does not seem realistic. Therefore, using purified enzymes, we reconstituted oxaloacetate metabolism in Synechocystis 6803 in vitro to reveal the regulatory mechanisms involved. Reconstitution of oxaloacetate metabolism revealed that pH, Mg2+ and phosphoenolpyruvate are important factors affecting the conversion of oxaloacetate in the TCA cycle. Biochemical analyses of the enzymes involved in oxaloacetate metabolism in this and previous studies revealed the biochemical mechanisms underlying the effects of these factors on oxaloacetate conversion. In addition, we clarified the function of two l‐malate dehydrogenase isozymes in oxaloacetate metabolism. These findings serve as a basis for various applications of the cyanobacterial TCA cycle.

中文翻译:

集胞藻三羧酸循环中草酰乙酸代谢的重建。PCC 6803:发现直接影响草酰乙酸转化的重要因素

三羧酸 (TCA) 循环是自然界中最重要的代谢途径之一。产氧光合自养细菌蓝藻具有不寻常的 TCA 循环。蓝藻中的 TCA 循环包含两种独特的酶,这些酶不属于其他生物体中的 TCA 循环。近年来,使用蓝藻从二氧化碳中可持续生产代谢物已被视为减少这种气体环境负担的一种手段。在蓝藻中,单细胞蓝藻集胞藻属。PCC 6803 ( Synechocystis 6803) 是可持续代谢物生产的最佳宿主。最近,在集胞藻中使用 TCA 循环产生代谢物6803 已执行。先前的研究表明,氧化和还原 TCA 循环的分支点草酰乙酸代谢在代谢物产生中起着关键作用。然而,在集胞藻6803 中调节草酰乙酸代谢的生化机制知之甚少。集胞藻6803 中草酰乙酸的浓度极低,因此草酰乙酸代谢的体内分析似乎不现实。因此,我们使用纯化的酶在体外重建了集胞藻6803中的草酰乙酸代谢,以揭示所涉及的调节机制。草酰乙酸代谢的重建表明 pH、Mg 2+和磷酸烯醇式丙酮酸是影响三氯乙酸循环中草酰乙酸转化的重要因素。在这项研究和之前的研究中,对参与草酰乙酸代谢的酶进行的生化分析揭示了这些因素对草酰乙酸转化影响的潜在生化机制。此外,我们阐明了两种l-苹果酸脱氢酶同工酶在草酰乙酸代谢中的功能。这些发现为蓝藻 TCA 循环的各种应用奠定了基础。
更新日期:2020-12-06
down
wechat
bug