5MZ8

Crystal structure of aldehyde dehydrogenase 21 (ALDH21) from Physcomitrella patens in complex with the reaction product succinate

5MZ8 の概要

• エントリーDOI: 10.2210/pdb5mz8/pdb
• 関連するPDBエントリー: 5MZ5
• 分子名称: aldehyde dehydrogenase 21, SUCCINIC ACID, 1,2-ETHANEDIOL, ... (6 entities in total)
• 機能のキーワード: rossmann fold, oxidoreductase, succinic semialdehyde dehydrogenase, nadp+ binding
• 由来する生物種: Physcomitrella patens subsp. patens (Moss)
• タンパク質・核酸の鎖数: 4
• 化学式量合計: 230679.58

構造登録者

Kopecny, D.,Vigouroux, A.,Briozzo, P.,Morera, S. (登録日: 2017-01-31, 公開日: 2017-08-09, 最終更新日: 2024-01-17)

主引用文献

Kopecna, M.,Vigouroux, A.,Vilim, J.,Koncitikova, R.,Briozzo, P.,Hajkova, E.,Jaskova, L.,von Schwartzenberg, K.,Sebela, M.,Morera, S.,Kopecny, D.
The ALDH21 gene found in lower plants and some vascular plants codes for a NADP(+) -dependent succinic semialdehyde dehydrogenase.
Plant J., 92:229-243, 2017

PubMed Abstract: Lower plant species including some green algae, non-vascular plants (bryophytes) as well as the oldest vascular plants (lycopods) and ferns (monilophytes) possess a unique aldehyde dehydrogenase (ALDH) gene named ALDH21, which is upregulated during dehydration. However, the gene is absent in flowering plants. Here, we show that ALDH21 from the moss Physcomitrella patens codes for a tetrameric NADP -dependent succinic semialdehyde dehydrogenase (SSALDH), which converts succinic semialdehyde, an intermediate of the γ-aminobutyric acid (GABA) shunt pathway, into succinate in the cytosol. NAD is a very poor coenzyme for ALDH21 unlike for mitochondrial SSALDHs (ALDH5), which are the closest related ALDH members. Structural comparison between the apoform and the coenzyme complex reveal that NADP binding induces a conformational change of the loop carrying Arg-228, which seals the NADP in the coenzyme cavity via its 2'-phosphate and α-phosphate groups. The crystal structure with the bound product succinate shows that its carboxylate group establishes salt bridges with both Arg-121 and Arg-457, and a hydrogen bond with Tyr-296. While both arginine residues are pre-formed for substrate/product binding, Tyr-296 moves by more than 1 Å. Both R121A and R457A variants are almost inactive, demonstrating a key role of each arginine in catalysis. Our study implies that bryophytes but presumably also some green algae, lycopods and ferns, which carry both ALDH21 and ALDH5 genes, can oxidize SSAL to succinate in both cytosol and mitochondria, indicating a more diverse GABA shunt pathway compared with higher plants carrying only the mitochondrial ALDH5.

PubMed: 28749584
DOI: 10.1111/tpj.13648

実験手法

X-RAY DIFFRACTION (2.2 Å)