EPR, electron spin echo envelope modulation, and electron nuclear double resonance studies of the 2Fe2S centers of the 2-halobenzoate 1,2-dioxygenase from Burkholderia (Pseudomonas) cepacia 2CBS.
The 2-halobenzoate 1,2-dioxygenase from Burkholderia (Pseudomonas) cepacia 2CBS (Fetzner, S., Müller, R., and Lingens, F. (1992) J. Bacteriol. 174, 279-290) contains both a ferredoxin-type and a Rieske-type 2Fe2S center. These two significantly different 2Fe2S clusters were characterized with respect to their EPR spectra, electrochemical properties (Rieske-type cluster with gz = 2.025, gy = 1.91, gx = 1.79, gav = 1.91, Em = -125 +/- 10 mV; ferredoxin-type center with gz = 2.05, gy = 1.96, gx = 1.89, gav = 1.97, Em = -200 +/- 10 mV) and pH dependence thereof. X band electron spin echo envelope modulation and electron nuclear double resonance spectroscopy was applied to study the interaction of the Rieske-type center of the 2-halobenzoate 1,2-dioxygenase with 14N and 1H nuclei in the vicinity of the 2Fe2S cluster. The results are compared to those obtained on the Rieske protein of the cytochrome b6f complex (Em = +320 mV) and the water-soluble ferredoxin (Em = -430 mV) of spinach chloroplasts, as typical representatives of the gav = 1.91 and gav = 1.96 class of 2Fe2S centers. Properties common to all Rieske-type clusters and those restricted to the respective centers in bacterial oxygenases are discussed.
Institut für Biophysik und Physikalische Biochemie, Universität Regensburg, Federal Republic of Germany.
A
A
Riedel
S
S
Fetzner
M
M
Rampp
F
F
Lingens
U
U
Liebl
J L
JL
Zimmermann
W
W
Nitschke
D016956:Burkholderia cepacia / Q000201:enzymology*; D004563:Electrochemistry; D004578:Electron Spin Resonance Spectroscopy; D007506:Iron-Sulfur Proteins / Q000737:chemistry*; D010105:Oxygenases / Q000737:chemistry*
D007506:Iron-Sulfur Proteins; D010105:Oxygenases; C072183:2-chlorobenzoate 1,2-dioxygenase