Publications

• Transcarboxylase: one of nature's early nanomachines.

  Carey P.R., Sonnichsen F.D., Yee V.C.

  The enzyme transcarboxylase (TC) catalyzes an unusual reaction; TC transfers a carboxylate group from methylmalonyl-CoA to pyruvate to form oxaloacetate and propionyl-CoA. Remarkably, to perform this task in Propionii bacteria Nature has created a large assembly made up of 30 polypeptides that tot ... >> More

  The enzyme transcarboxylase (TC) catalyzes an unusual reaction; TC transfers a carboxylate group from methylmalonyl-CoA to pyruvate to form oxaloacetate and propionyl-CoA. Remarkably, to perform this task in Propionii bacteria Nature has created a large assembly made up of 30 polypeptides that totals 1.2 million daltons. In this nanomachine the catalytic machinery is repeated 6-12 times over using ordered arrays of replicated subunits. The latter are sites of the half reactions. On the so-called 12S subunit a biotin cofactor accepts carboxylate, - CO2-, from methylmalonyl-CoA. The carboxylated-biotin then translocates to a second subunit, the 5S, to deliver the carboxylate to pyruvate. We have not yet characterized the intact nanomachine, however, using a battery of biophysical techniques, we have been able to derive novel,and sometimes unexpected, structural and mechanistic insights into the 12S and 5S subunits. Similar insights have been obtained for the small 1.3S subunit that acts as the biotin carrier linking the 12S and 5S forms. Interestingly, some of these insights gained for the 12S and 5S subunits carry over to related mammalian enzymes such as human propionyl-CoA carboxylase and human pyruvate carboxylase, respectively, to provide a rationale for their malfunction in disease-related mutations. << Less

  IUBMB Life 56:575-583(2004) [PubMed] [EuropePMC]

• Transcarboxylase: its quaternary structure and the role of the biotinyl subunit in the assembly of the enzyme and in catalysis.

  Wood H.G., Kumar G.K.

  Ann N Y Acad Sci 447:1-22(1985) [PubMed] [EuropePMC]

• Determination of the binding specificity of the 12S subunit of the transcarboxylase by saturation transfer difference NMR.

  Peikert C., Seeger K., Bhat R.K., Berger S.

  In this study we present the characterization of the interaction of biotin and methylmalonyl-CoA (MMCoA) with the carboxyltransferase subunit (12S) from the transcarboxylase (TC) from Propionibacterium shermanii. This biotin dependent multienzyme complex catalyses the transfer of carbon dioxide fr ... >> More

  In this study we present the characterization of the interaction of biotin and methylmalonyl-CoA (MMCoA) with the carboxyltransferase subunit (12S) from the transcarboxylase (TC) from Propionibacterium shermanii. This biotin dependent multienzyme complex catalyses the transfer of carbon dioxide from methylmalonyl-CoA (MMCoA) to pyruvate. The Saturation Transfer Difference NMR (STD) technique was performed to determine the binding epitope from biotin and MMCoA to the 12S subunit. We could show by titrations during STD experiments that biotin and MMCoA bind cooperatively in one binding pocket. << Less

  Org Biomol Chem 2:1777-1781(2004) [PubMed] [EuropePMC]

• New and easy strategy for cloning, expression, purification, and characterization of the 5S subunit of transcarboxylase from Propionibacterium f. shermanii.

  Kumar Bhat R., Berger S.

  Methylmalonyl CoA-oxalacetate transcarboxylase (EC 2. 1. 3. 1) from Propionibacterium f. shermanii is a biotin dependent enzyme which transfers CO2 from methylmalonyl-CoA (MMCoA) to pyruvate via a carboxylated biotin group to form oxalacetate. It is composed of three subunits, the central cylindri ... >> More

  Methylmalonyl CoA-oxalacetate transcarboxylase (EC 2. 1. 3. 1) from Propionibacterium f. shermanii is a biotin dependent enzyme which transfers CO2 from methylmalonyl-CoA (MMCoA) to pyruvate via a carboxylated biotin group to form oxalacetate. It is composed of three subunits, the central cylindrical hexameric 12S subunit, the outer six dimeric 5S subunit, and the twelve 1.3S linkers. We here report the cloning, sequencing, expression, and purification of the 5S subunit. The gene was identified by matching the amino acid sequence with that of deposited in the NCBI database. For cloned 5S subunit sequence shows regions of high homology with that of pyruvate carboxylase and oxaloacetate decarboxylase. The gene encoding the 5S subunit was cloned into the pTXB1 vector. The expressed 5S subunit was purified to apparent homogeneity by a single step process by using Intein mediated protein ligation (IPL) method. The cloned 5S gene encodes a protein of 505 amino acids and of M(r) 55,700. << Less

  Prep Biochem Biotechnol 37:13-26(2007) [PubMed] [EuropePMC]

• THE ROLE OF TRANSCARBOXYLATION IN PROPIONIC ACID FERMENTATION.

  Swick R.W., Wood H.G.

  Proc Natl Acad Sci U S A 46:28-41(1960) [PubMed] [EuropePMC]