The mechanism of the anaerobic Escherichia coli ribonucleotide reductase investigated with nuclear magnetic resonance spectroscopy.
During the reduction of ribonucleotides with [3H]formate by the class III anaerobic ribonucleotide reductase from Escherichia coli tritium appears in water and not in the product deoxyribonucleotide. In D2O, deuterium replaces the OH-group at carbon-2' with retention of configuration. In addition we find 1-2% deuterium in the 3'-position demonstrating a small exchange of this hydrogen with the protons of water during catalysis. Class I and II enzymes catalyze identical reactions. Members of the three classes of reductases apparently use the same chemical mechanism in spite of having completely different protein structures.
Eliasson
R
R
Department of Biochemistry 1, Medical Nobel Institute, MBB Karolinska Institute, Stockholm, Sweden.
Reichard
P
P
Mulliez
E
E
Ollagnier
S
S
Fontecave
M
M
Liepinsh
E
E
Otting
G
G
D003841:Deoxycytidine / Q000737:chemistry; D004926:Escherichia coli / Q000201:enzymology*; D006859:Hydrogen / Q000737:chemistry; D017665:Hydroxyl Radical / Q000737:chemistry; D009682:Magnetic Resonance Spectroscopy; D012264:Ribonucleotide Reductases / Q000737:chemistry*; D013237:Stereoisomerism
D003841:Deoxycytidine; D017665:Hydroxyl Radical; D006859:Hydrogen; D012264:Ribonucleotide Reductases