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Full-Text Articles in Life Sciences
Novel Insights Into The Biotin Carboxylase Domain Reactions Of Pyruvate Carboxylase From Rhizobium Etli, Tonya N. Zeczycki, Ann L. Menefee, Abdussalam Adina-Zada, Sarawut Jitrapakdee, Kathy H. Surinya, John C. Wallace, Paul V. Attwood, Martin St. Maurice, W Wallace Cleland
Novel Insights Into The Biotin Carboxylase Domain Reactions Of Pyruvate Carboxylase From Rhizobium Etli, Tonya N. Zeczycki, Ann L. Menefee, Abdussalam Adina-Zada, Sarawut Jitrapakdee, Kathy H. Surinya, John C. Wallace, Paul V. Attwood, Martin St. Maurice, W Wallace Cleland
Biological Sciences Faculty Research and Publications
The catalytic mechanism of the MgATP-dependent carboxylation of biotin in the biotin carboxylase domain of pyruvate carboxylase from R. etli (RePC) is common to the biotin-dependent carboxylases. The current site-directed mutagenesis study has clarified the catalytic functions of several residues proposed to be pivotal in MgATP-binding and cleavage (Glu218 and Lys245), HCO3 − deprotonation (Glu305 and Arg301), and biotin enolization (Arg353). The E218A mutant was inactive for any reaction involving the BC domain and the E218Q mutant exhibited a 75-fold decrease in kcat for both pyruvate carboxylation and the full reverse reaction. The E305A mutant also showed a 75- and …