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The Role Of Biotin And Oxamate In The Carboxyltransferase Reaction Of Pyruvate Carboxylase, Adam D. Lietzan, Yi Lin, Martin St. Maurice
The Role Of Biotin And Oxamate In The Carboxyltransferase Reaction Of Pyruvate Carboxylase, Adam D. Lietzan, Yi Lin, Martin St. Maurice
Biological Sciences Faculty Research and Publications
Pyruvate carboxylase (PC) is a biotin-dependent enzyme that catalyzes the MgATP-dependent carboxylation of pyruvate to oxaloacetate, an important anaplerotic reaction in central metabolism. During catalysis, carboxybiotin is translocated to the carboxyltransferase domain where the carboxyl group is transferred to the acceptor substrate, pyruvate. Many studies on the carboxyltransferase domain of PC have demonstrated an enhanced oxaloacetate decarboxylation activity in the presence of oxamate and it has been shown that oxamate accepts a carboxyl group from carboxybiotin during oxaloacetate decarboxylation. The X-ray crystal structure of the carboxyltransferase domain from Rhizobium etli PC reveals that oxamate is positioned in the active site …
Functionally Diverse Biotin-Dependent Enzymes With Oxaloacetate Decarboxylase Activity, Adam D. Lietzan, Martin St. Maurice
Functionally Diverse Biotin-Dependent Enzymes With Oxaloacetate Decarboxylase Activity, Adam D. Lietzan, Martin St. Maurice
Biological Sciences Faculty Research and Publications
Biotin-dependent enzymes catalyze carboxylation, decarboxylation and transcarboxylation reactions that participate in the primary metabolism of a wide range of organisms. In all cases, the overall reaction proceeds via two half reactions that take place in physically distinct active sites. In the first half-reaction, a carboxyl group is transferred to the 1-N′ of a covalently tethered biotin cofactor. The tethered carboxybiotin intermediate subsequently translocates to a second active site where the carboxyl group is either transferred to an acceptor substrate or, in some bacteria and archaea, is decarboxylated to biotin and CO2 in order to power the export of sodium …