在两种C4草中,多个高度表达的基酸碳化酶基因具有不同的酶动力学特性
Robert J DiMario1, Ashley N Kophs1, Anthony J A Apalla1
1School of Biological Sciences, Washington State University, Pullman, WA 99164, USA.
Annals of botany
|September 7, 2023
概括
两种C4草,Panicum miliaceum和 Echinochloa colona,拥有两种高度表达的酸 (PEP) 核糖酶 (PEPC) 基因. 在PEPC中氨基酸替代改变了其全调节,揭示了C4光合作用的多种进化路径.
科学领域:
- 植物生物化学 植物生物化学
- 光合作用研究研究光合作用.
- 分子进化的分子进化.
背景情况:
- 烯酸 (PEP) 碳氧化酶 (PEPC) 对于C4光合作用中的碳度机制 (CCM) 是至关重要的.
- 通常情况下,单个PEPC基因产物在C4植物的中细胞中驱动CCM.
- 这项研究研究了两种C4草,Panicum miliaceum和Echinochloa colona,每种都具有两个高度表达的PEPC基因.
研究的目的:
- 描述E. 结肠和P. miliaceum中两种最丰富的PEPCs的运动性质.
- 了解PEPC的氨基酸结构如何影响其功能,特别是在响应全调节时.
- 探索C4草中多个PEPC基因的进化影响.
主要方法:
- 在细菌表达等离子体中,合成了来自E.colona和P.miliaceum丰富的PEPC蛋白的编码序列.
- 通过局部指导的PCR突变产生点突变,向保存的氨基酸残留物.
- 使用膜入口质谱和光谱测试分析了半净化植物PEPC的动力特性.
主要成果:
- 这两种P. miliaceumPEPCs (PmPPC1,PmPPC2) 由于其高序列相同性 (>95%),具有相似的动力特性.
- 这两种E.大肠杆菌PEPCs (EcPPC1,EcPPC2) 显示出明显不同的动力特性,其序列相同度为~78%.
- 在保存的N端血清和残留890的替代物改变了PEPC对全调节者的反应.
结论:
- 在P. miliaceum中存在两种高度表达的C4Ppc基因可能是密切相关物种基因组组合的结果.
- 在PEPC的全抑制敏感性的自然变化绕过了保存的残留物890.
- 这表明C4植物具有增强的酸盐耐受性和修改的运动性质的替代进化途径.
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