3SYL

Crystal structure of the AAA+ protein CbbX, native structure

3SYL の概要

• エントリーDOI: 10.2210/pdb3syl/pdb
• 関連するPDBエントリー: 3SYK 3zuh
• EMDBエントリー: 1932
• 分子名称: Protein CbbX, SULFATE ION (3 entities in total)
• 機能のキーワード: photosynthesis, rubisco activase, aaa+ protein, calvin cycle, chaperone
• 由来する生物種: Rhodobacter sphaeroides
• タンパク質・核酸の鎖数: 2
• 化学式量合計: 70010.96

構造登録者

Mueller-Cajar, O.,Stotz, M.,Wendler, P.,Hartl, F.U.,Bracher, A.,Hayer-Hartl, M. (登録日: 2011-07-18, 公開日: 2011-11-09, 最終更新日: 2023-09-13)

主引用文献

Mueller-Cajar, O.,Stotz, M.,Wendler, P.,Hartl, F.U.,Bracher, A.,Hayer-Hartl, M.
Structure and function of the AAA+ protein CbbX, a red-type Rubisco activase.
Nature, 479:194-199, 2011

PubMed Abstract: Ribulose 1,5-bisphosphate carboxylase/oxygenase (Rubisco) catalyses the fixation of atmospheric CO(2) in photosynthesis, but tends to form inactive complexes with its substrate ribulose 1,5-bisphosphate (RuBP). In plants, Rubisco is reactivated by the AAA(+) (ATPases associated with various cellular activities) protein Rubisco activase (Rca), but no such protein is known for the Rubisco of red algae. Here we identify the protein CbbX as an activase of red-type Rubisco. The 3.0-Å crystal structure of unassembled CbbX from Rhodobacter sphaeroides revealed an AAA(+) protein architecture. Electron microscopy and biochemical analysis showed that ATP and RuBP must bind to convert CbbX into functionally active, hexameric rings. The CbbX ATPase is strongly stimulated by RuBP and Rubisco. Mutational analysis suggests that CbbX functions by transiently pulling the carboxy-terminal peptide of the Rubisco large subunit into the hexamer pore, resulting in the release of the inhibitory RuBP. Understanding Rubisco activation may facilitate efforts to improve CO(2) uptake and biomass production by photosynthetic organisms.

PubMed: 22048315
DOI: 10.1038/nature10568

実験手法

X-RAY DIFFRACTION (3 Å)