tailieunhanh - Báo cáo khoa học: Purification of three aminotransferases from Hydrogenobacter thermophilusTK-6 – novel types of alanine or glycine aminotransferase Enzymes and catalysis

Aminotransferases catalyse synthetic and degradative reactions of amino acids, and serve as a key linkage between central carbon and nitrogen metabolism in most organisms. In this study, three aminotransferases (AT1, AT2 and AT3) were purified and characterized fromHydrogenobacter thermophilus, a hydrogen-oxidizing chemolithoautotrophic bacterium, which has been reported to possess unique features in its carbon and nitrogen anabolism. | ễFEBS Journal Purification of three aminotransferases from Hydrogenobacter thermophilus TK-6 - novel types of alanine or glycine aminotransferase Enzymes and catalysis Masafumi Kameya Hiroyuki Arai Masaharu Ishii and Yasuo Igarashi Department of Biotechnology The University of Tokyo Japan Keywords 2-oxo acid amino acid aminotransferase Hydrogenobacter thermophilus nitrogen anabolism Correspondence M. Ishii Department of Biotechnology The University of Tokyo Yayoi 1-1-1 Bunkyo-ku Tokyo 113-8657 Japan Fax 81 3 5841 5272 Tel 81 3 5841 5143 E-mail amishii@ Received 6 January 2010 revised 27 January 2010 accepted 2 February 2010 doi Aminotransferases catalyse synthetic and degradative reactions of amino acids and serve as a key linkage between central carbon and nitrogen metabolism in most organisms. In this study three aminotransferases AT1 AT2 and AT3 were purified and characterized from Hydrogenobacter thermophilus a hydrogen-oxidizing chemolithoautotrophic bacterium which has been reported to possess unique features in its carbon and nitrogen anabolism. AT1 AT2 and AT3 exhibited glutamate oxaloacetate aminotransferase glutamate pyruvate aminotransferase and alanine glyoxylate aminotransferase activities respectively. In addition both AT1 and AT2 catalysed a glutamate glyoxylate aminotransferase reaction. Interestingly phylogenetic analysis showed that AT2 belongs to aminotransferase family IV whereas known glutamate pyruvate aminotransferases and gluta-mate glyoxylate aminotransferases are members of family Iy. In contrast AT3 was classified into family I distant from eukaryotic alanine glyoxylate aminotransferases which belong to family IV. Although Thermococcus litoralis alanine glyoxylate aminotransferase is the sole known example of family I alanine glyoxylate aminotransferases it is indicated that this alanine glyoxylate aminotransferase and AT3 are derived from distinct lineages within family I because .

• Báo cáo khoa học
• Scientific reports
• scientific research
• molecular Biology
• catalysis
• aminotransferase
• Hydrogenobacter
• biochemistry
• enzymatic
• biological activities