Mechanistic Studies of Type II IPP Isomerase

II型IPP异构酶的机理研究

• 批准号: 6876583
• 负责人: Steven C. Rothman
• 金额: $ 4.83万
• 依托单位: UNIVERSITY OF UTAH
• 依托单位国家: 美国
• 财政年份: 2004
• 资助国家: 美国
• 起止时间: 2004-04-01 至 2007-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6876583
• 关键词: NAD(H) phosphate; X ray crystallography; active sites; bacteria; bacterial proteins; chemical structure function; deuterium; enzyme activity; enzyme mechanism; flavin mononucleotide; gene mutation; isomerase; oxidoreductase; postdoctoral investigator; site directed mutagenesis; spectrometry; stereochemistry

DESCRIPTION (provided by applicant): A recent report describes the cloning and preliminary characterization of an unusual flavin mononucleotide (FMN) dependent enzyme, the type II isopentenyl diphosphate (IPP) isomerase. IPP isomerases interconvert isopentenyl diphosphate and dimethylallyl diphosphate, the metabolic building blocks for a wide array of biological isoprenoid compounds. The newly identified type II enzyme represents an attractive antimicrobial drug target as sequence analyses suggest that it is essential in the pathogen Staphylococcus aureus and is not present in humans. The initial study with the type II IPP isomerase indicated that catalysis requires both FMN and NADPH. The role is these two cofactors is unclear, given that isomerization does not entail a net oxidation/reduction and that the type l isomerase catalyzes a proton addition-proton elimination reaction that does not include a transient oxidation/reduction. This proposed work intends to elucidate the functions of the two cofactors, the chemical mechanism, and the roles of active site residues in the reaction catalyzed by type II isopentenyl diphosphate isomerase from Synechocystis sp. PCC 6803.

描述（由申请人提供）： 最近的一份报告描述了不寻常的黄素单核苷酸（FMN）依赖性酶的克隆和初步表征，即II型异戊烯基二磷酸（IPP）异构酶。 IPP异构酶互连异戊烯基二磷酸和二甲基二磷酸二磷酸，这是各种生物类异型化合物的代谢构件。新鉴定的II型酶代表了一个有吸引力的抗菌药物靶标，因为序列分析表明，它在金黄色葡萄球菌中至关重要，并且在人类中不存在。对II型IPP异构酶的初步研究表明，催化需要FMN和NADPH。鉴于异构化不需要净氧化/还原，并且L类异构酶会催化质子添加蛋白 - 普罗氏蛋白消除反应，该反应不包括瞬态氧化/还原。这项工作旨在阐明两个辅助因子的功能，化学机理以及活性位点残基在反应中由II型异戊烯基二磷酸异构酶催化的反应中的作用。 PCC 6803。