1ZZH

Structure of the fully oxidized di-heme cytochrome c peroxidase from R. capsulatus

1ZZH の概要

• エントリーDOI: 10.2210/pdb1zzh/pdb
• 分子名称: cytochrome c peroxidase, CALCIUM ION, ZINC ION, ... (5 entities in total)
• 機能のキーワード: cytochrome c peroxidase, heme groups, oxidoreductase
• 由来する生物種: Rhodobacter capsulatus
• タンパク質・核酸の鎖数: 4
• 化学式量合計: 145628.56

構造登録者

De Smet, L.,Savvides, S.N.,Van Horen, E.,Pettigrew, G.,Van Beeumen, J.J. (登録日: 2005-06-14, 公開日: 2005-11-29, 最終更新日: 2024-03-13)

主引用文献

De Smet, L.,Savvides, S.N.,Van Horen, E.,Pettigrew, G.,Van Beeumen, J.J.
Structural and mutagenesis studies on the cytochrome c peroxidase from Rhodobacter capsulatus provide new insights into structure-function relationships of bacterial di-heme peroxidases
J.Biol.Chem., 281:4371-4379, 2006

PubMed Abstract: Cytochrome c peroxidases (CCP) play a key role in cellular detoxification by catalyzing the reduction of hydrogen peroxide to water. The di-heme CCP from Rhodobacter capsulatus is the fastest enzyme (1060 s(-1)), when tested with its physiological cytochrome c substrate, among all di-heme CCPs characterized to date and has, therefore, been an attractive target to investigate structure-function relationships for this family of enzymes. Here, we combine for the first time structural studies with site-directed mutagenesis and spectroscopic studies of the mutant enzymes to investigate the roles of amino acid residues that have previously been suggested to be important for activity. The crystal structure of R. capsulatus at 2.7 Angstroms in the fully oxidized state confirms the overall molecular scaffold seen in other di-heme CCPs but further reveals that a segment of about 10 amino acids near the peroxide binding site is disordered in all four molecules in the asymmetric unit of the crystal. Structural and sequence comparisons with other structurally characterized CCPs suggest that flexibility in this part of the molecular scaffold is an inherent molecular property of the R. capsulatus CCP and of CCPs in general and that it correlates with the levels of activity seen in CCPs characterized, thus, far. Mutagenesis studies support the spin switch model and the roles that Met-118, Glu-117, and Trp-97 play in this model. Our results help to clarify a number of aspects of the debate on structure-function relationships in this family of bacterial CCPs and set the stage for future studies.

PubMed: 16314410
DOI: 10.1074/jbc.M509582200

実験手法

X-RAY DIFFRACTION (2.7 Å)