Preliminary crystallographic analysis and further characterization of a dodecaheme cytochrome c from Desulfovibrio desulfuricans ATCC 27774

Citation:
Coelho, AV, PM Matias, LC Sieker, J. Morais, MA Carrondo, J. Lampreia, C. Costa, JJG Moura, I. Moura, and J. LeGall. "Preliminary crystallographic analysis and further characterization of a dodecaheme cytochrome c from Desulfovibrio desulfuricans ATCC 27774." ACTA CRYSTALLOGRAPHICA SECTION D-BIOLOGICAL CRYSTALLOGRAPHY. 52 (1996): 1202-1208.

Abstract:

{Dodecaheme cytochrome c has been purified from Desulfovibrio (D.) desulfuricans ATCC 27774 cells grown under both nitrate and sulfate-respiring conditions. Therefore, it is likely to play a role in the electron-transfer system of both respiratory chains. Its molecular mass (37 768 kDa) was determined by electrospray mass spectrometry. Its first 39 amino acids were sequenced and a motif was found between amino acids 32 and 37 that seems to exist in all the cytochromes of the c3 type from sulfate-reducing bacteria sequenced at present. The midpoint redox potentials of this cytochrome were estimated to be -68, -120, -248 and -310 mV. Electron paramagnetic resonance spectroscopy of the oxidized cytochrome shows several low-spin components with a g(max) spreading from 3.254 to 2.983. Two crystalline forms were obtained by vapour diffusion from a solution containing 2% PEG 6000 and 0.25-0.75 M acetate buffer pH = 5.5. Both crystals belong to monoclinic space groups: one is PZ,, with a = 61.00