TY - JOUR
T1 - Binding of cob(II)alamin to the adenosylcobalamin-dependent ribonucleotide reductase from Lactobacillus leichmannii
T2 - Identification of dimethylbenzimidazole as the axial ligand
AU - Lawrence, Christopher C.
AU - Gerfen, Gary J.
AU - Samano, Vicente
AU - Nitsche, Rainer
AU - Robins, Morris J.
AU - Rétey, János
AU - Stubbe, Jo Anne
PY - 1999/3/12
Y1 - 1999/3/12
N2 - The ribonucleoside triphosphate reductase (RTPR) from Lactobacillus leichmannii catalyzes the reduction of nucleoside 5'-triphosphates to 2'- deoxynucleoside 5'-triphosphates and uses coenzyme B12, adenosylcobalamin (AdoCbl), as a cofactor. Use of a mechanism-based inhibitor, 2'-deoxy-2'- methylenecytidine 5'-triphosphate, and isotopically labeled RTPR and AdoCbl in conjunction with EPR spectroscopy has allowed identification of the lower axial ligand of cob(II)alamin when bound to RTPR. In common with the AdoCbl- dependent enzymes catalyzing irreversible heteroatom migrations and in contrast to the enzymes catalyzing reversible carbon skeleton rearrangements, the dimethylbenzimidazole moiety of the cofactor is not displaced by a protein histidine upon binding to RTPR.
AB - The ribonucleoside triphosphate reductase (RTPR) from Lactobacillus leichmannii catalyzes the reduction of nucleoside 5'-triphosphates to 2'- deoxynucleoside 5'-triphosphates and uses coenzyme B12, adenosylcobalamin (AdoCbl), as a cofactor. Use of a mechanism-based inhibitor, 2'-deoxy-2'- methylenecytidine 5'-triphosphate, and isotopically labeled RTPR and AdoCbl in conjunction with EPR spectroscopy has allowed identification of the lower axial ligand of cob(II)alamin when bound to RTPR. In common with the AdoCbl- dependent enzymes catalyzing irreversible heteroatom migrations and in contrast to the enzymes catalyzing reversible carbon skeleton rearrangements, the dimethylbenzimidazole moiety of the cofactor is not displaced by a protein histidine upon binding to RTPR.
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U2 - 10.1074/jbc.274.11.7039
DO - 10.1074/jbc.274.11.7039
M3 - Article
C2 - 10066759
AN - SCOPUS:0033548547
SN - 0021-9258
VL - 274
SP - 7039
EP - 7042
JO - Journal of Biological Chemistry
JF - Journal of Biological Chemistry
IS - 11
ER -