1CCG

CONSTRUCTION OF A BIS-AQUO HEME ENZYME AND REPLACEMENT WITH EXOGENOUS LIGAND

1CCG の概要

• エントリーDOI: 10.2210/pdb1ccg/pdb
• 分子名称: CYTOCHROME C PEROXIDASE, PROTOPORPHYRIN IX CONTAINING FE, IMIDAZOLE, ... (4 entities in total)
• 機能のキーワード: oxidoreductase(h2o2(a))
• 由来する生物種: Saccharomyces cerevisiae (baker's yeast)
• 細胞内の位置: Mitochondrion matrix: P00431
• タンパク質・核酸の鎖数: 1
• 化学式量合計: 33830.42

構造登録者

Mcree, D.E.,Jensen, G.M.,Fitzgerald, M.M.,Siegel, H.A.,Goodin, D.B. (登録日: 1994-05-04, 公開日: 1994-07-31, 最終更新日: 2024-02-07)

主引用文献

McRee, D.E.,Jensen, G.M.,Fitzgerald, M.M.,Siegel, H.A.,Goodin, D.B.
Construction of a bisaquo heme enzyme and binding by exogenous ligands.
Proc.Natl.Acad.Sci.USA, 91:12847-12851, 1994

PubMed Abstract: The crystal structure of the His-175-->Gly (H175G) mutant of cytochrome-c peroxidase (EC 1.11.1.5), missing its only heme ligand, reveals that the histidine is replaced by solvent to give a bisaquo heme protein. This protein retains some residual activity, which can be stimulated or inhibited by addition of exogenous ligands. Structural analysis confirms the binding of imidazole to the heme at the position of the wild-type histidine ligand. This imidazole complex reacts readily with hydrogen peroxide to produce a radical species with novel properties. However, reactivation in this complex is incomplete (approximately 5%), which, in view of the very similar structures of the wild-type and the H175G/imidazole forms, implies a critical role for tethering of the axial ligand in catalysis. This study demonstrates the feasibility of constructing heme enzymes with no covalent link to the protein and with unnatural ligand replacements. Such enzymes may prove useful in studies of electron transfer mechanisms and in the engineering of novel heme-based catalysts.

PubMed: 7809133
DOI: 10.1073/pnas.91.26.12847

実験手法

X-RAY DIFFRACTION (2.1 Å)