Publications

• Glycine metabolism by rat liver mitochondria. Reconstruction of the reversible glycine cleavage system with partially purified protein components.

  Motokawa Y., Kikuchi G.

  Arch Biochem Biophys 164:624-633(1974) [PubMed] [EuropePMC]

• Cloning and nucleotide sequence of the gcv operon encoding the Escherichia coli glycine-cleavage system.

  Okamura-Ikeda K., Ohmura Y., Fujiwara K., Motokawa Y.

  P-protein, H-protein and T-protein of the glycine cleavage system have been purified from Escherichia coli. Their N-terminal amino acid sequences were determined, and a set of oligonucleotide probes was designed for gene cloning. The nucleotide sequence of a fragment of DNA around the 62-min regio ... >> More

  P-protein, H-protein and T-protein of the glycine cleavage system have been purified from Escherichia coli. Their N-terminal amino acid sequences were determined, and a set of oligonucleotide probes was designed for gene cloning. The nucleotide sequence of a fragment of DNA around the 62-min region of the E. coli chromosome, containing genes for the components of the glycine-cleavage system has been determined. The sequence includes three structural genes encoding T-protein (363 amino acids, 40013 Da), H-protein (128 amino acids, 13679 Da) and P-protein (956 amino acids, 104240 Da). These genes are named gcvT, gcvH and gcvP, respectively. They are organized in the above-mentioned order on the same strand of DNA with short intercistronic sequences. The presence of a potential promoter preceding gcvT and a typical rho-independent terminator sequence following gcvP indicated that the three genes constitute a single operon. Each component of the E. coli glycine-cleavage system exhibits considerable amino acid sequence similarity with the animal and plant counterparts. When the plasmid containing the gcv operon was transfected in E. coli cells, the gene products of gcvT, gcvH and gcvP were overexpressed under the direction of the promoter of the gcv operon. However, bacteria harboring the plasmid that contained the gcv operon without the promoter region and the 5' terminal portion of gcvT failed to overexpress any of the three components. << Less

  Eur. J. Biochem. 216:539-548(1993) [PubMed] [EuropePMC]

• Mechanism of the glycine cleavage reaction. Further characterization of the intermediate attached to H-protein and of the reaction catalyzed by T-protein.

  Fujiwara K., Okamura-Ikeda K., Motokawa Y.

  Glycine is converted to carbon dioxide and an intermediate attached to H-protein in the P-protein-catalyzed partial reaction of the glycine cleavage reaction (Fujiwara, K., and Motokawa, Y. (1983) J. Biol. Chem. 258, 8156-8162). The studies presented in this communication indicate that the amino g ... >> More

  Glycine is converted to carbon dioxide and an intermediate attached to H-protein in the P-protein-catalyzed partial reaction of the glycine cleavage reaction (Fujiwara, K., and Motokawa, Y. (1983) J. Biol. Chem. 258, 8156-8162). The studies presented in this communication indicate that the amino group of glycine is retained in the intermediate and released as ammonia in the second partial reaction catalyzed by T-protein. The formation of ammonia accompanies the stoichiometric formation of 5,10-methylenetetrahydrofolate from the methylene carbon of glycine and tetrahydrofolate. Kinetic studies show that the reaction proceeds through a sequential mechanism. Km values for the intermediate complex and tetrahydrofolate are 2.2 and 50 microM, respectively. In the absence of tetrahydrofolate, T-protein catalyzes the stoichiometric formation of ammonia and formaldehyde from the intermediate although the velocity is extremely low. Km value for the intermediate complex in the absence of tetrahydrofolate is 10.3 microM, about 4-fold higher than the value in the presence of tetrahydrofolate. The addition of tetrahydrofolate increased the rate about 2400-fold. The modification of the free lipoyl sulfhydryl group with N-ethylmaleimide caused the intermediate complex inactive. The lipoyl sulfhydryl group seems to be essential for both P-protein- and T-protein-catalyzed partial reactions. << Less

  J Biol Chem 259:10664-10668(1984) [PubMed] [EuropePMC]

• Purification and characterization of chicken liver T-protein, a component of the glycine cleavage system.

  Okamura-Ikeda K., Fujiwara K., Motokawa Y.

  T-protein, a component of the glycine cleavage system, has been purified to apparent homogeneity from chicken liver mitochondria. The molecular weight was 37,000 by sedimentation equilibrium centrifugation and 38,000 by gel filtration. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis gave ... >> More

  T-protein, a component of the glycine cleavage system, has been purified to apparent homogeneity from chicken liver mitochondria. The molecular weight was 37,000 by sedimentation equilibrium centrifugation and 38,000 by gel filtration. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis gave a molecular weight of 41,000, indicating that the protein is composed of a single polypeptide. A partial specific volume of 0.73 ml/g was obtained from the amino acid composition. The absorbance coefficient, A1%280nm, is 6.63 in 50 mM potassium phosphate buffer, pH 7.0. T-protein is a basic protein having a pI value of 9.8 and relatively rich in arginine rather than lysine. The protein catalyzed the degradation of the protein-bound intermediate (-CH2NH2 moiety of glycine) to a 1-carbon unit and NH3. The reaction is dependent on tetrahydrofolate (H4-folate). Apparent Km values for the intermediate and H4-folate were 3.7 microM and 0.17 mM, respectively. T-protein associated with H-protein forming a complex which was composed of one molecule each of T-protein and H-protein. Formation of the complex was not affected by the modification of the cysteinyl residues on H-protein with N-ethylmaleimide. << Less

  J Biol Chem 257:135-139(1982) [PubMed] [EuropePMC]

  This publication is cited by 1 other entry.

• The mitochondrial glycine cleavage system. Functional association of glycine decarboxylase and aminomethyl carrier protein.

  Hiraga K., Kikuchi G.

  J. Biol. Chem. 255:11671-11676(1980) [PubMed] [EuropePMC]

  This publication is cited by 1 other entry.