Substrate translocation for translational editing

用于翻译编辑的底物易位

• 批准号: 6792300
• 负责人: William F Waas
• 金额: $ 4.3万
• 依托单位: SCRIPPS RESEARCH INSTITUTE, THE
• 依托单位国家: 美国
• 财政年份: 2004
• 资助国家: 美国
• 起止时间: 2004-03-01 至 2007-02-28
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6792300
• 关键词: Escherichia coli; active sites; aminoacid tRNA ligase; enzyme substrate; gene induction /repression; genetic translation; intermolecular interaction; point mutation; postdoctoral investigator; protein transport; transfer RNA; translation factor

DESCRIPTION (provided by applicant): During translation the genetic code is interpreted into polypeptide cell components. Mistakes at this level can have deleterious effects on cell viability by altering protein function and stability. Aminoacyl-tRNA synthetases (AARSs) are directly involved in translational fidelity. They couple amino acids to tRNA molecules bearing corresponding anti-codon sequences. Several AARSs have evolved interesting proofreading mechanism to maintain high substrate specificity in vivo. Specifically, a handful-possess a hydrolytic editing activity to correct errors initially made at their synthetic sites. The editing and synthetic activities of AARSs occur at distally located active sites. Therefore, misacylated substrates must "translocate" between catalytic centers. Substrate translocation has been demonstrated essential, but is poorly understood. This proposal describes experiments that will elucidate events surrounding the process. First, an in vivo saturation mutagenesis screen will be used to identify components of the translocation machinery. The components will then be characterized biochemically to determine their role in substrate translocation. The goal is to produce a refined model for substrate translocation and AARS catalyzed editing.

描述（由申请人提供）： 在翻译过程中，遗传密码被解释为多肽细胞成分。该级别的错误可以通过改变蛋白质功能和稳定性对细胞生存能力产生有害影响。氨基酰基-TRNA合成酶（AARSS）直接参与转化保真度。他们将氨基酸与伴有相应抗氧化序列的tRNA分子息息。几种AARS已经发展出有趣的校对机制，以保持体内高底物特异性。具体而言，少数可以使用水解编辑活动，以纠正最初在其合成位点犯的错误。 AARS的编辑和合成活动发生在远端的活性位点。因此，催化中心之间必须“迁移”降低的底物。底物易位已被证明是必不可少的，但知之甚少。该建议描述了将阐明该过程事件的实验。 首先，将使用体内饱和诱变筛选来识别易位机械的组件。然后，将以生化特征来确定其在底物易位中的作用。目的是生产一个用于底物易位的精制模型，并催化AARS催化编辑。