GENETIC APPROACHES TO PROTEIN-NUCLEIC ACID INTERACTIONS

蛋白质-核酸相互作用的遗传学方法

• 批准号: 3271740
• 负责人: PAUL R SCHIMMEL
• 金额: $ 24.56万
• 依托单位: MASSACHUSETTS INSTITUTE OF TECHNOLOGY
• 依托单位国家: 美国
• 财政年份: 1977
• 资助国家: 美国
• 起止时间: 1977-03-01 至 1993-02-28
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/3271740
• 关键词: DNA; Escherichia coli; X ray crystallography; acylation; aminoacid; aminoacid tRNA ligase; aminoacyl tRNA; binding proteins; biochemical evolution; chemical fingerprinting; crosslink; enzyme induction /repression; enzyme mechanism; enzyme structure; genetic manipulation; genetic mapping; hybrid enzyme; ligase; mutant; nucleic acid sequence; peptides; protein engineering; protein sequence; transfer RNA; yeasts

Rules of the genetic code are established by the matching of trinucleotide sequences with specific amino acids. This is done by the interaction of aminoacyl tRNA synthetases with transfer RNAs. This specificity of this interaction enables the synthetases to attach amino acids to the cognate transfer RNAs. The transfer RNAs encode nucleotide triplet anticodons which correspond to specific amino acids. For some, perhaps most, transfer RNAs, the anticodon per se is not the primary site by which the synthetases recognize their cognate transfer RNAs. This means that other sites in the molecule are critical. Mutagenesis of tRNA and its cognate enzyme is used to define further the sites that are sensitive to recognition. Advantage is taken of structural data on transfer RNA and of emerging structural data on aminoacyl tRNA synthetases. Also used are data which have defined regions in both molecules that are significant for recognition. Chimeric enzymes are tested to determine whether specific regions of one enzyme can function within the context of the structural framework of another enzyme. Sequences that are critical for tRNA recognition may be swapped between enzymes. The use of heterologous yeast-E. coli systems in vivo expands considerably the ability to define nucleotides that determine the identity of a tRNA. These systems also can be developed to make chimeric yeast-E. coli aminoacyl tRNA synthetases.

遗传密码的规则是由 三核苷酸序列与特定氨基酸的匹配 acids. 这是通过氨酰tRNA 合成酶与转移RNA。 这种特殊性 相互作用使得合成酶能够将氨基酸连接到 同源转移RNA。 转移RNA编码 核苷酸三联体反密码子，其对应于特定的 个氨基酸 对于一些，也许是大多数，转移RNA， 反密码子本身不是主要的位点， 合成酶识别它们的同源转移RNA。 这 意味着分子中的其他位点也很关键。 tRNA及其同源酶的突变用于定义 进一步的网站是敏感的识别。 优点是 转移RNA的结构数据和新出现的结构数据 关于氨酰tRNA合成酶的数据。 还使用的是数据， 两种分子中的特定区域， 识别. 测试嵌合酶以确定是否 一种酶的特定区域可以在 另一种酶的结构框架。 的序列 对于tRNA识别至关重要的基因可能在酶之间交换。 的 异源酵母-E.大肠杆菌系统在体内扩展 在很大程度上定义核苷酸的能力， 确定tRNA的身份。 这些系统也可以是 用来制造嵌合酵母-E大肠杆菌氨酰tRNA 合成酶