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PubMed:10880349 JSONTXT

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PMID_GLOBAL

Id Subject Object Predicate Lexical cue
T1 0-83 Sentence denotes Identification of active-site residues in Bradyrhizobium japonicum malonamidase E2.
T2 84-186 Sentence denotes Malonamidase (MA) E2 was previously purified and characterized from Bradyrhizobium japonicum USDA 110.
T3 187-278 Sentence denotes The gene encoding this enzyme has been cloned, sequenced and expressed in Escherichia coli.
T4 279-357 Sentence denotes The recombinant MAE2 was purified to homogeneity from the transformed E. coli.
T5 358-474 Sentence denotes The biochemical properties of the recombinant enzyme are essentially identical to those from wild-type B. japonicum.
T6 475-611 Sentence denotes A database search showed that the MAE2 protein has a high sequence similarity with the common signature sequences of the amidase family.
T7 612-724 Sentence denotes The only exception is that the aspartic residue in these signature sequences is replaced by a glutamine residue.
T8 725-895 Sentence denotes In order to identify amino acid residues essential for enzyme activity, a series of site-directed mutagenesis studies and steady-state kinetic experiments were performed.
T9 896-1016 Sentence denotes Gln(195), Ser(199), Cys(207) and Lys(213) of the common signature sequences were selected for site-directed mutagenesis.
T10 1017-1199 Sentence denotes Among the mutants, Q195D, Q195E and S199C showed less than 0.02% of the k(cat) value of the wild-type enzyme, and S199A, Q195L and Q195N exhibited no detectable catalytic activities.
T11 1200-1378 Sentence denotes Mutants (K213L, K213R and K213H) obtained by replacement of the only conserved basic residue, Lys(213), in the signature sequences, also displayed significant reductions (approx.
T12 1379-1439 Sentence denotes 380-fold) in k(cat) value, whereas C207A kept full activity.
T13 1440-1596 Sentence denotes These results suggest that MAE2 may catalyse hydrolysis of malonamate by a novel catalytic mechanism, in which Gln(195), Ser(199) and Lys(213) are involved.