APPLICATION OF NMR TO THE STUDY OF XYLOSE SYNTHASES

核磁共振在木糖合酶研究中的应用

• 批准号: 8361815
• 负责人: JOHN GLUSHKA
• 金额: $ 0.18万
• 依托单位: UNIVERSITY OF GEORGIA
• 依托单位国家: 美国
• 财政年份: 2011
• 资助国家: 美国
• 起止时间: 2011-02-01 至 2012-01-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8361815
• 关键词: Animals; Bacteria; Enzymes; Eukaryota; Funding; Genes; Grant; Homologous Gene; NADH; National Center for Research Resources; Pentoses; Plants; Principal Investigator; Prokaryotic Cells; Ralstonia solanacearum; Research; Research Infrastructure; Resources; Source; United States National Institutes of Health; Uridine Diphosphate Glucuronic Acid; Uridine Diphosphate Sugars; Uridine Diphosphate Xylose; Xylose; apiose; cost; plant fungi

This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. Primary support for the subproject and the subproject's principal investigator may have been provided by other sources, including other NIH sources. The Total Cost listed for the subproject likely represents the estimated amount of Center infrastructure utilized by the subproject, not direct funding provided by the NCRR grant to the subproject or subproject staff. The enzymes involved in converting UDP-GlcA to other UDP-sugars are well described in eukaryotes, but less is known in prokaryotes. Here we identify and characterize a gene (RsU4kpxs) from Ralstonia solanacearum str. GMI1000, which encodes a dual-function enzyme, UDP-4-keto-pentose/UDP-xylose synthase (UXS). One activity is to decarboxylate UDP-glucuronic acid to UDP-¿-L-threo-pentopyranosyl-4"-ulose (UDP-4-keto-pentose) in the presence of NAD+. The second converts UDP-4-keto-pentose and NADH to UDP-xylose and NAD+, albeit at a lower rate. The identification of the R. solanacearum enzyme enables us to propose that the ancestral UXS (as well as UDP-apiose synthase or UAXS) diverged into two distinct enzymatic activities in early bacteria. This separation gave rise to the current Uxs in animal, fungus and plant as well as to the plant Uaxs homologs.

这个子项目是许多利用资源的研究子项目之一 由NIH/NCRR资助的中心拨款提供。子项目的主要支持 而子项目的主要调查员可能是由其他来源提供的， 包括其它NIH来源。 列出的子项目总成本可能 代表子项目使用的中心基础设施的估计数量， 而不是由NCRR赠款提供给子项目或子项目工作人员的直接资金。 参与将UDP-GlcA转化为其他UDP-糖的酶在真核生物中有很好的描述，但在原核生物中知之甚少。在这里，我们确定和表征的基因（RsU 4kpxs）从青枯雷尔氏菌str.GMI1000，它编码的双功能酶，UDP-4-酮戊糖/UDP-木糖合酶（UXS）。一种活性是在NAD+存在下将UDP-葡萄糖醛酸脱羧为UDP-<$-L-苏型-吡喃戊糖基-4”-酮糖（UDP-4-酮-戊糖）。第二个将UDP-4-酮戊糖和NADH转化为UDP-木糖和NAD+，尽管速率较低。对该菌的鉴定进行了研究。青枯菌酶使我们能够提出祖先UXS（以及UDP-芹菜糖合酶或UAXS）在早期细菌中分化成两种不同的酶活性。这种分离产生了目前在动物、真菌和植物中的Uxs以及植物Uaxs同系物。