title: A stereochemical study of the mechanism of activation of donor oligonucleotides by RNA ligase from bacteriophage T4 infected Escherichia coli.
abstract: RNA ligase from bacteriophage T4 infected Escherichia coli catalyzes the activation of adenosine 3',5'-bisphosphate (representing the donor oligonucleotide) by adenosine 5'-[(S)-alpha-17O,alpha,alpha-18O2]triphosphate with retention of configuration at P alpha. Since single-step enzyme-catalyzed nucleotidyl transfer reactions proceed with inversion, this stereochemical result provides support for a double displacement mechanism involving an adenylyl-enzyme intermediate as proposed previously from isotope exchange experiments.
mesh_terms: D000227:Adenine Nucleotides / Q000378:metabolism; D000249:Adenosine Monophosphate / Q000378:metabolism; D000255:Adenosine Triphosphate / Q000378:metabolism; D004789:Enzyme Activation; D004926:Escherichia coli / Q000201:enzymology*; D043564:Inorganic Pyrophosphatase; D007700:Kinetics; D009682:Magnetic Resonance Spectroscopy; D009841:Oligonucleotides / Q000378:metabolism*; D010103:Oxygen Isotopes; D011118:Polynucleotide Ligases / Q000378:metabolism*; D011755:Pyrophosphatases / Q000378:metabolism; D011130:RNA Ligase (ATP) / Q000378:metabolism*; D013604:T-Phages / Q000201:enzymology*
chemical_list: D000227:Adenine Nucleotides; D009841:Oligonucleotides; D010103:Oxygen Isotopes; C017990:adenosine 3'-diphosphate 5'-diphosphate; D000249:Adenosine Monophosphate; D000255:Adenosine Triphosphate; D011755:Pyrophosphatases; D043564:Inorganic Pyrophosphatase; D011118:Polynucleotide Ligases; D011130:RNA Ligase (ATP)