4UAV

Crystal structure of CbbY (AT3G48420) from Arabidobsis thaliana

4UAV の概要

• エントリーDOI: 10.2210/pdb4uav/pdb
• 分子名称: Haloacid dehalogenase-like hydrolase domain-containing protein At3g48420, MAGNESIUM ION (3 entities in total)
• 機能のキーワード: haloacid dehalogenase (had) hydrolase superfamily, phosphatase, hydrolase
• 由来する生物種: Arabidopsis thaliana (Thale cress)
• 細胞内の位置: Plastid, chloroplast : Q94K71
• タンパク質・核酸の鎖数: 1
• 化学式量合計: 26803.10

構造登録者

Bracher, A.,Sharma, A.,Starling-Windhof, A.,Hartl, F.U.,Hayer-Hartl, M. (登録日: 2014-08-11, 公開日: 2014-12-31, 最終更新日: 2023-12-20)

主引用文献

Bracher, A.,Sharma, A.,Starling-Windhof, A.,Hartl, F.U.,Hayer-Hartl, M.
Degradation of potent Rubisco inhibitor by selective sugar phosphatase.
Nat.Plants, 1:14002-14002, 2015

PubMed Abstract: Ribulose-1,5-bisphosphate carboxylase/oxygenase (Rubisco) catalyses the conversion of atmospheric carbon dioxide into organic compounds in photosynthetic organisms. Alongside carboxylating the five-carbon sugar ribulose-1,5-bisphosphate (RuBP)(1-3), Rubisco produces a small amount of xylulose-1,5-bisphosphate (XuBP), a potent inhibitor of Rubisco(4). The AAA+ protein Rubisco activase removes XuBP from the active site of Rubisco in an ATP-dependent process(5,6). However, free XuBP rapidly rebinds to Rubisco, perpetuating its inhibitory effect. Here, we combine biochemical and structural analyses to show that the CbbY protein of the photosynthetic bacterium Rhodobacter sphaeroides and Arabidopsis thaliana is a highly selective XuBP phosphatase. We also show that CbbY converts XuBP to the non-inhibitory compound xylulose-5-phosphate, which is recycled back to RuBP. We solve the crystal structures of CbbY from R. sphaeroides and A. thaliana, and through mutational analysis show that the cap domain of the protein confers the selectivity for XuBP over RuBP. Finally, in vitro experiments with CbbY from R. sphaeroides reveal that CbbY cooperates with Rubisco activase to prevent a detrimental build-up of XuBP at the Rubisco active site. We suggest that CbbY, which is conserved in algae and plants, is an important component of the cellular machinery that has evolved to deal with the shortcomings of the ancient enzyme Rubisco.

PubMed: 27246049
DOI: 10.1038/nplants.2014.2

実験手法

X-RAY DIFFRACTION (1.3 Å)