1IWI

Putidaredoxin-Binding Stablilizes an Active Conformer of Cytochrome P450cam in its Reduced State; Crystal Structure of Cytochrome P450cam

1IWI の概要

• エントリーDOI: 10.2210/pdb1iwi/pdb
• 関連するPDBエントリー: 1IWJ 1IWK
• 分子名称: CYTOCHROME P450-CAM, PROTOPORPHYRIN IX CONTAINING FE, CAMPHOR, ... (4 entities in total)
• 機能のキーワード: putidaredoxin binding site, cytochrome p450cam, riken structural genomics/proteomics initiative, rsgi, structural genomics, oxidoreductase
• 由来する生物種: Pseudomonas putida
• タンパク質・核酸の鎖数: 1
• 化学式量合計: 47488.79

構造登録者

Nagano, S.,Shimada, H.,Tarumi, A.,Hishiki, T.,Kimata-Ariga, Y.,Egawa, T.,Park, S.-Y.,Adachi, S.,Shiro, Y.,Ishimura, Y.,RIKEN Structural Genomics/Proteomics Initiative (RSGI) (登録日: 2002-05-15, 公開日: 2002-06-05, 最終更新日: 2023-12-27)

主引用文献

Nagano, S.,Shimada, H.,Tarumi, A.,Hishiki, T.,Kimata-Ariga, Y.,Egawa, T.,Suematsu, M.,Park, S.-Y.,Adachi, S.,Shiro, Y.,Ishimura, Y.
Infrared spectroscopic and mutational studies on putidaredoxin-induced conformational changes in ferrous CO-P450cam
Biochemistry, 42:14507-14514, 2003

PubMed Abstract: Ferrous-carbon monoxide bound form of cytochrome P450cam (CO-P450cam) has two infrared (IR) CO stretching bands at 1940 and 1932 cm(-1). The former band is dominant (>95% in area) for CO-P450cam free of putidaredoxin (Pdx), while the latter band is dominant (>95% in area) in the complex of CO-P450cam with reduced Pdx. The binding of Pdx to CO-P450cam thus evokes a conformational change in the heme active site. To study the mechanism involved in the conformational change, surface amino acid residues Arg79, Arg109, and Arg112 in P450cam were replaced with Lys, Gln, and Met. IR spectroscopic and kinetic analyses of the mutants revealed that an enzyme that has a larger 1932 cm(-1) band area upon Pdx-binding has a larger catalytic activity. Examination of the crystal structures of R109K and R112K suggested that the interaction between the guanidium group of Arg112 and Pdx is important for the conformational change. The mutations did not change a coupling ratio between the hydroxylation product and oxygen consumed. We interpret these findings to mean that the interaction of P450cam with Pdx through Arg112 enhances electron donation from the proximal ligand (Cys357) to the O-O bond of iron-bound O(2) and, possibly, promotes electron transfer from reduced Pdx to oxyP450cam, thereby facilitating the O-O bond splitting.

PubMed: 14661963
DOI: 10.1021/bi035410p

実験手法

X-RAY DIFFRACTION (2 Å)