2ZBY

Crystal structure of vitamin D hydroxylase cytochrome P450 105A1 (R84A mutant)

2ZBY の概要

• エントリーDOI: 10.2210/pdb2zby/pdb
• 関連するPDBエントリー: 2ZBX 2ZBZ
• 分子名称: Cytochrome P450-SU1, PROTOPORPHYRIN IX CONTAINING FE (3 entities in total)
• 機能のキーワード: p450, beta prism, heme, iron, metal-binding, monooxygenase, oxidoreductase
• 由来する生物種: Streptomyces griseolus
• タンパク質・核酸の鎖数: 1
• 化学式量合計: 45608.23

構造登録者

Sugimoto, H.,Shinkyo, R.,Hayashi, K.,Yoneda, S.,Yamada, M.,Kamakura, M.,Ikushiro, S.,Shiro, Y.,Sakaki, T. (登録日: 2007-10-30, 公開日: 2008-04-08, 最終更新日: 2023-11-01)

主引用文献

Sugimoto, H.,Shinkyo, R.,Hayashi, K.,Yoneda, S.,Yamada, M.,Kamakura, M.,Ikushiro, S.,Shiro, Y.,Sakaki, T.
Crystal Structure of CYP105A1 (P450SU-1) in Complex with 1alpha,25-Dihydroxyvitamin D3
Biochemistry, 47:4017-4027, 2008

PubMed Abstract: Vitamin D 3 (VD 3), a prohormone in mammals, plays a crucial role in the maintenance of calcium and phosphorus concentrations in serum. Activation of VD 3 requires 25-hydroxylation in the liver and 1alpha-hydroxylation in the kidney by cytochrome P450 (CYP) enzymes. Bacterial CYP105A1 converts VD 3 into 1alpha,25-dihydroxyvitamin D 3 (1alpha,25(OH) 2D 3) in two independent reactions, despite its low sequence identity with mammalian enzymes (<21% identity). The present study determined the crystal structures of a highly active mutant (R84A) of CYP105A1 from Streptomyces griseolus in complex and not in complex with 1alpha,25(OH) 2D 3. The compound 1alpha,25(OH) 2D 3 is positioned 11 A from the iron atom along the I helix within the pocket. A similar binding mode is observed in the structure of the human CYP2R1-VD 3 complex, indicating a common substrate-binding mechanism for 25-hydroxylation. A comparison with the structure of wild-type CYP105A1 suggests that the loss of two hydrogen bonds in the R84A mutant increases the adaptability of the B' and F helices, creating a transient binding site. Further mutational analysis of the active site reveals that 25- and 1alpha-hydroxylations share residues that participate in these reactions. These results provide the structural basis for understanding the mechanism of the two-step hydroxylation that activates VD 3.

PubMed: 18314962
DOI: 10.1021/bi7023767

実験手法

X-RAY DIFFRACTION (1.6 Å)