Molecular Mechanisms of Human DNA Polymerase B Catalysis, Fidelity and Selective

人类 DNA 聚合酶 B 催化、保真度和选择性的分子机制

• 批准号: 8591712
• 负责人: MYRON GOODMAN
• 金额: $ 58.05万
• 依托单位: UNIVERSITY OF SOUTHERN CALIFORNIA
• 依托单位国家: 美国
• 财政年份: 2013
• 资助国家: 美国
• 起止时间: 2013-09-03 至 2018-08-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8591712
• 关键词: Active Sites; Catalysis; Cell-Free System; Chemicals; DNA-Directed DNA Polymerase; Electronics; Electrostatics; Family; Grant; Human; Instruction; Kinetics; Left; Malignant Neoplasms; Measurement; Molecular; Oxygen; Polymerase; Property; Research; analog; base; bisphosphonate; cancer cell; human DNA; innovation; member; mutant; repair enzyme; research study; theories; tool

DNA polymerase mechanisms of base selection and catalysis are explored using a tool-kit of dNTP analogs that have bisphosphonates in place of the B,Y-bridge oxygen. These analogs are Pol B substrates that have leaving groups with widely dispirate electronic properties, pKa4 values ranging from 7.8 to 12.3, enabling us to use presteady state kinetic measurements to determine the selection of right and wrong deoxynucleotides occurring at the chemical transition state. Especially important members of the toolkit include all four individually synthesized (R)- and (S)-B,Y-CHF and B,Y-CHCI diastereomers. Our recent observation of a pronounced stereoselection for (R)-CHF in Pol B involving an electrostatic interaction of F with Arg183, unique to family X pols such as Pol B, serves as the impetus for a

DNA聚合酶的碱基选择和催化机制的探索使用的dNTP类似物的工具包，具有双膦酸盐的地方的B，Y-桥氧。这些类似物是Pol B底物，其离去基团具有广泛的电子性质，pKa 4值范围为7.8至12.3，使我们能够使用presteady状态动力学测量来确定在化学过渡态发生的正确和错误的脱氧核苷酸的选择。该工具包的特别重要的成员包括所有四种单独合成的（R）-和（S）-B，Y-CHF和B，Y-CHCl非对映体。我们最近观察到Pol B中（R）-CHF的明显立体选择性，涉及F与Arg 183的静电相互作用，这是X家族Pol如Pol B所特有的，这是Pol B中（R）-CHF的立体选择性的推动力。