• 主题
高级搜索  >
历史搜索 清空历史
首页> 外文期刊>Applied and Environmental Microbiology >Identification of the yqhE andyafB Genes Encoding Two 2,5-Diketo-d-Gluconate Reductases inEscherichia coli
【24h】

Identification of the yqhE andyafB Genes Encoding Two 2,5-Diketo-d-Gluconate Reductases inEscherichia coli

机译：大肠杆菌中编码两个2，5-二酮-d-葡萄糖酸还原酶的yqhE和yafB基因的鉴定

获取原文
           
页面导航
  • 摘要
  • 著录项
  • 相似文献
  • 相关主题

摘要

The identification of a gene (yiaE) encoding 2-ketoaldonate reductase (2KR) in our previous work led to the hypothesis that Escherichia coli has other ketogluconate reductases including 2,5-diketo-d-gluconate reductase (25DKGR) and to study of the related ketogluconate metabolism. By using the deduced amino acid sequences of 5-diketo-d-gluconate reductase (5KDGR) of Gluconobacter oxydans and 25DKGR ofCorynebacterium sp., protein databases were screened to detect homologous proteins. Among the proteins of E. coli, an oxidoreductase encoded by yjgU and having 56% similarity to 5KDGR of G. oxydans and two hypothetical oxidoreductases encoded by yqhE and yafB and having 49.8 and 42% similarity, respectively, to 25DKGR ofCorynebacterium sp. were detected. Recently, theyjgU gene was identified as encoding 5KDGR and renamedidnO (C. Bausch, N. Peekhaus, C. Utz, T. Blais, E. Murray, T. Lowary, and T. Conway, J. Bacteriol. 180:3704–3710, 1998). The pathways involved in the metabolism of ketogluconate by E. coli have been predicted by biochemical analysis of purified enzymes and chemical analysis of the pathway intermediates. The gene products of yqhE and yafB were identified as 25DKGR-A, and 25DKGR-B, respectively, catalyzing the reduction of 25KDG to 2-keto-l-gulonate (2KLG). The native 25DKGR-A, 25DKGR-B, and 5KDGR had apparent molecular weights of about 30,000, 30,000, and 54,000, respectively. In sodium dodecyl sulfate-polyacrylamide gel electrophoresis gels, all three enzymes showed protein bands with a molecular weight of about 29,000, which indicated that 25DKGR-A, 25DKGR-B, and 5KDGR may exist as monomeric, monomeric, and dimeric proteins, respectively. The optimum pHs for reduction were 7.5, 7.0, and 8.0, respectively. The 5KDGR was active with NADH, whereas 25DKGR-A and 25DKGR-B were active with NADPH as a preferred electron donor. 25DKG can be converted to 5KDG by 2KR, which is then reduced tod-gluconate by 5KDGR. The pathways were compared with those of Erwinia sp. and Corynebacterium sp. A BLAST search of published and incomplete microbial genome sequences revealed that the ketogluconate reductases and their related metabolism may be widespread in many species.
机译：在我们先前的工作中，鉴定出一个编码2-酮醛酸还原酶（2KR）的基因（yiaE），导致了这样一个假设，即大肠杆菌还具有其他酮葡糖酸还原酶，包括2,5-二酮-d-葡糖酸还原酶（25DKGR），并进行了研究。相关的酮葡萄糖酸代谢。通过使用氧化葡糖杆菌的5-二酮-d-葡萄糖酸还原酶（5KDGR）和棒状杆菌的25DKGR的推导氨基酸序列，筛选蛋白质数据库以检测同源蛋白质。在大肠杆菌的蛋白质中，由yjgU编码的氧化还原酶与oxydans的5KDGR具有56％的相似性，以及由yqhE和yafB编码的两种假定的氧化还原酶，分别与棒状杆菌25DKGR的49.8和42％相似。被检测到。最近，他们被鉴定为编码5KDGR并重命名为didnO（C. Bausch，N. Peekhaus，C.Utz，T.Blais，E.Murray，T.Lowary，and T.Conway，J.Bacteriol。180：3704–3710 （1998年）。通过纯化的酶的生化分析和途径中间体的化学分析已经预测了参与大肠杆菌酮葡糖酸代谢的途径。 yqhE和yafB的基因产物分别鉴定为25DKGR-A和25DKGR-B，催化25KDG还原为2-酮-1-古洛糖酸酯（2KLG）。天然的25DKGR-A，25DKGR-B和5KDGR的表观分子量分别约为30,000、30,000和54,000。在十二烷基硫酸钠-聚丙烯酰胺凝胶电泳凝胶中，所有三种酶均显示分子量约为29,000的蛋白带，这表明25DKGR-A，25DKGR-B和5KDGR可能分别以单体，单体和二聚体蛋白形式存在。还原的最佳pH分别为7.5、7.0和8.0。 5KDGR对NADH具有活性，而25DKGR-A和25DKGR-B对NADPH作为优选的电子供体具有活性。可以通过2KR将25DKG转换为5KDG，然后通过5KDGR将其还原为葡萄糖。将途径与欧文氏菌的途径进行了比较。和棒杆菌属。对已发表和不完整的微生物基因组序列进行的BLAST搜索显示，酮葡糖酸还原酶及其相关代谢可能在许多物种中广泛存在。

著录项

相似文献

  • 外文文献
  • 中文文献
  • 专利
获取原文

客服邮箱：kefu@zhangqiaokeyan.com

京公网安备：11010802029741号 ICP备案号：京ICP备15016152号-6 六维联合信息科技 (北京) 有限公司©版权所有

  • 客服微信

  • 服务号