Calcium-dependent heme structure in the reduced forms of the bacterial cytochrome c peroxidase from Paracoccus pantotrophus.

This work reports for the first time a resonance Raman study of the mixed-valence and fully reduced forms of Paracoccus pantotrophus bacterial cytochrome c peroxidase. The spectra of the active mixed-valence enzyme show changes in the structure of the ferric peroxidatic heme compared to the fully oxidized enzyme; these differences are observed upon reduction of the electron-transferring heme and upon full occupancy of the calcium site. For the mixed-valence form in the absence of Ca(2+), the peroxidatic heme is six-coordinate and low-spin on the basis of the frequencies of the structure-sensitive Raman lines: the enzyme is inactive.

Redefining Paracoccus denitrificans and Paracoccus pantotrophus and the case for a reassessment of the strains held by international culture collections.

An outline of the current taxonomic diversity of the genus Paracoccus is presented. A definitive summary is given of the valid type strains of Paracoccus denitrificans and Paracoccus pantotrophus and of culture collection strains that can be assigned to these species. The case is established for a critical reassessment of the P.

Activation and catalysis of the di-heme cytochrome c peroxidase from Paracoccus pantotrophus.

Bacterial cytochrome c peroxidases contain an electron transferring (E) heme domain and a peroxidatic (P) heme domain. All but one of these enzymes are isolated in an inactive oxidized state and require reduction of the E heme by a small redox donor protein in order to activate the P heme. Here we present the structures of the inactive oxidized and active mixed valence enzyme from Paracoccus pantotrophus.

A copper protein and a cytochrome bind at the same site on bacterial cytochrome c peroxidase.

Pseudoazurin binds at a single site on cytochrome c peroxidase from Paracoccus pantotrophus with a K(d) of 16.4 microM at 25 degrees C, pH 6.0, in an endothermic reaction that is driven by a large entropy change.

Paracoccus pantotrophus pseudoazurin is an electron donor to cytochrome c peroxidase.

The gene for pseudoazurin was isolated from Paracoccus pantotrophus LMD 52.44 and expressed in a heterologous system with a yield of 54.3 mg of pure protein per liter of culture.

Crystallization and preliminary X-ray diffraction analysis of a dihaem cytochrome c peroxidase from Paracoccus denitrificans.

Cytochrome c peroxidase was isolated from Paracoccus denitrificans and purified to homogeneity in three steps prior to crystallization. Two different diffraction-quality crystal forms were obtained by the hanging-drop vapour-diffusion method using a number of screening conditions. The best (needle-shaped) crystal form is suitable for structural studies and was grown from solutions containing 20% PEG 8000, 0.

Electron transfer complexes of cytochrome c peroxidase from Paracoccus denitrificans containing more than one cytochrome.

According to the model proposed in previous papers [Pettigrew, G. W., Prazeres, S.

The electron transfer complexes of cytochrome c peroxidase from Paracoccus denitrificans.

We have used microcalorimetry and analytical ultracentrifugation to test the model proposed in Pettigrew et al. [(1999) J. Biol.

Ca2+ and the bacterial peroxidases: the cytochrome c peroxidase from Pseudomonas stutzeri.

The production of cytochrome c peroxidase (CCP) from Pseudomonas ( Ps.) stutzeri (ATCC 11607) was optimized by adjusting the composition of the growth medium and aeration of the culture. The protein was isolated and characterized biochemically and spectroscopically in the oxidized and mixed valence forms.