Minority Predoctoral Fellowship Program

少数族裔博士前奖学金计划

• 批准号: 7062628
• 负责人: LAKENYA F WILLIAMS
• 金额: $ 3.06万
• 依托单位: TEXAS A&M UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2006
• 资助国家: 美国
• 起止时间: 2006-01-01 至 2008-12-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7062628
• 关键词: Escherichia coli; Salmonella typhimurium; active sites; adenosine; adenosine triphosphate; amidation /deamidation; bacterial proteins; enzyme activity; enzyme mechanism; enzyme structure; enzyme substrate; isomerase; ligase; microorganism metabolism; predoctoral investigator; uronate; vitamin B12

DESCRIPTION (provided by applicant): The overall goal for the project is to study the detailed mechanisms of uronate isomerase and adenosyl- cobyric acid synthetase. Uronate isomerase has been identified as a member of the amidohydrolase superfamily, in which most members catalyze hydrolysis reactions. The reaction of uronate isomerase differs from other family members in that it catalyzes the isomerization of glucuronic and galacturonic acid to fructuronic and tagaturonic acid, respectively. The existence of an isomerase in the amidohydrolase superfamily provides an excellent example of divergent evolution of enzyme function. The modifications to the active site that enables an isomerization reaction in this superfamily are of significant interest. Adenosyl- cobyric acid synthetase (CbiP) catalyzes the sequential amidation of carboxylate groups b, d, e, and g of adenosyl-cobyrinic acid a,c-diamide. The mechanism of CbiP is interesting because it catalyzes chemical reactions at multiple sites within the same substrate. Preliminary data suggest that the amidation of these carboxylate groups is ordered and dissociative. The specific order of amidation and the structural basis for this selectivity will be elucidated.

描述（由申请人提供）：该项目的总体目标是研究uronate异构酶和腺苷酸酸合成酸合成酶的详细机制。 uronate异构酶已被鉴定为酰胺水解酶超家族的成员，其中大多数成员都会催化水解反应。 uronate异构酶的反应与其他家族成员不同，因为它分别催化了葡萄糖醛酸和半乳酸化的异构化对果糖剂和tagaturonic酸的异构化。异构酶在酰胺水解酶超家族中的存在提供了一个很好的例子，证明了酶功能的发散演化。在该超家族中实现异构化反应的活动位点的修改引起了重大关注。腺苷酸酸合成酶（CBIP）催化了羧酸酯基团B，D，E和G的顺序亚类腺苷酸A，C-贝醇酸A，C二胺。 CBIP的机制很有趣，因为它会催化同一基材内多个位点的化学反应。初步数据表明，这些羧酸酯基团的抑制作用是有序的和解离的。将阐明这种选择性的特定胺化顺序和结构基础。