阿拉伯芥的植物半胱胺酸氧化酶 AtPCO 1之生物物理
與結構特性研究

第七群乙烯反應因子是植物在無氧環境誘導的轉錄因子。當植物在無氧的狀態下，他們只會透過無氧呼吸產生的小量三磷酸腺苷（ATP）去維持它的生命。這一個系統可以保護植物免受水災的危害。第七群乙烯反應因子是否存在是由植物的N-end rule pathway來決定。第七群乙烯反應因子都有一個共同的特徵，它們的氨基酸序列都是從MCGG開始。這個特徵賦與他們可以被修飾，氧化及降解。第七群乙烯反應因子的降解必需要經過一系列的酵素，但這些酵素不只是單純為第七群乙烯反應因子而存在。這群酵素裡只有Plant cysteine oxidase (PCO)是只處理無氧基因。PCO 是對於植物轉為生長或者保護模式的最關鍵酵素。這個開關可以讓植物逃離全球暖化造成的大量自然災害。PCO 1是這個研究的目標，他是植物PCO中表現量最大的。同時，PCO 1亦是能夠被無氧環境誘導表達的B型PCO. 為了完全明白PCO 1, 他的晶體結構是必不可少。經過了無數次的序列和結晶條件優化，最終蛋白結晶成功被找出來。

關鍵字

蛋白結晶；全球暖化； AtPCO1 ； ERF VII ； N-end rule pathway

並列摘要

Group VII ethylene response factor (ERF) is hypoxia genes transcription factor of plants [1]. When plants enter hypoxia, they only produce a tiny amount of ATP from the anaerobic respiration to survive. This system protects the plants from waterlogging or flooding [2]. The N-End rule pathway decides the existence of ERF 7. ERF group 7 a standard feature; their first few amino acids are MCGG. This feature endows them to be modified, oxidized, and degraded [3]. Degradation of ERF group 7 has to undergo a series of enzymatic modification and degradation, but these enzymes not only process ERF group 7 [4]. The enzyme which only deals with hypoxia genes is plant cysteine oxidase (PCO). In other words, PCO is the critical enzyme for plants to switch to growth or protection mode with minimal side effects. This switch can let plants escape from the natural disasters caused by global warming. PCO 1 is our research target, the richest cysteine oxidase in plants. Also, it is B-Type PCO which leads to induction of massive anaerobic genes [5]. For the complete understanding of PCO 1, its crystal structure is indispensable. After numerous sequence editing and crystallization modification, crystals were finally found in some conditions.

並列關鍵字

AtPCO1 ； ERF VII ； N-end rule pathway ； crystallization ； global warming

參考文獻

1. Giuntoli, B. and P. Perata, Group VII Ethylene Response Factors in Arabidopsis: Regulation and Physiological Roles. Plant Physiol, 2018. 176(2): p. 1143-1155.

Google Scholar

2. White, M.D., et al., Structures of Arabidopsis thaliana oxygen-sensing plant cysteine oxidases 4 and 5 enable targeted manipulation of their activity. Proc Natl Acad Sci U S A, 2020. 117(37): p. 23140-23147.

Google Scholar

3. White, M.D., et al., The plant cysteine oxidases from Arabidopsis thaliana are kinetically tailored to act as oxygen sensors. J Biol Chem, 2018. 293(30): p. 11786-11795.