Exemplar Abstract for Methylophilus methylotrophus Jenkins et al. 1987.

2003 ◽  
Author(s):  
Charles Thomas Parker ◽  
Dorothea Taylor ◽  
George M Garrity
Keyword(s):  
Methylophilus Methylotrophus

Unusual redox properties of electron-transfer flavoprotein from Methylophilus methylotrophus

Biochemistry ◽  
1989 ◽  
Vol 28 (21) ◽  
pp. 8582-8587 ◽  
Author(s):  
Colleen M. Byron ◽  
Marian T. Stankovich ◽  
Mazhar Husain ◽  
Victor L. Davidson
Keyword(s):  
Electron Transfer ◽  
Redox Properties ◽  
Methylophilus Methylotrophus ◽  
Electron Transfer Flavoprotein

scholarly journals Cytochrome c″ isolated from Methylophilus methylotrophus. An example of bis-histidine-co-ordinated Fe3+ haem, with near-perpendicular orientation of the ligands

1990 ◽  
Vol 270 (2) ◽  
pp. 413-417 ◽  
Author(s):  
M J Berry ◽  
S J George ◽  
A J Thomson ◽  
H Santos ◽  
D L Turner
Keyword(s):  
Low Temperature ◽  
Cytochrome C ◽  
High Spin ◽  
Magnetic Circular Dichroism ◽  
Electron Paramagnetic Resonance Spectroscopy ◽  
Water Soluble ◽  
Reduced Form ◽  
Resonance Spectroscopy ◽  
Methylophilus Methylotrophus ◽  
Perpendicular Orientation

Cytochrome c″ (Methylophilus methylotrophus) is a soluble protein, Mr 15,000, possessing one haem which is high-spin in the reduced state but switches to a low-spin form on oxidation. Low-temperature electron-paramagnetic-resonance spectroscopy of the oxidized state shows a low-spin signal at gz = 3.65 with a folded line-shape typical of a haem of low rhombicity, and the near-infrared magnetic-circular-dichroism (m.c.d.) spectra reveal an unusually intense (delta epsilon = 400 M-1.cm-1 at 5 T, 4.2 K) charge-transfer band at 1560 nm, establishing that the oxidized haem is co-ordinated by two His residues in a near-perpendicular orientation. This conformation is well established for transmembrane b cytochromes, but this appears to be the first example in a water-soluble cytochrome. The low-temperature m.c.d. spectra of the reduced form of the protein confirms that the haem contains a high-spin Fe2+ ligated by one His residue. The redox-linked spin-state change releases a His group. Since this residue is likely to bind a proton at pH values less than 6.5, this cytochrome may provide a useful model of a molecular mechanism of a redox-linked proton uptake and release process.

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