Pyrrolysine, a novel genetically encoded amino acid

吡咯赖氨酸，一种新型基因编码氨基酸

• 批准号: 7188521
• 负责人: JOSEPH Adrian KRZYCKI
• 金额: $ 28.35万
• 依托单位: OHIO STATE UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2005
• 资助国家: 美国
• 起止时间: 2005-03-01 至 2009-02-28
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7188521
• 关键词: Achievement; Amber; Amino Acids; Amino Acyl-tRNA Synthetases; Aminoacylation; Archaea; Biochemical Genetics; Biogenesis; Catalysis; Characteristics; Charge; Codon Nucleotides; Crystallography; Cytoplasm; Cytosol; Elements; Enzymes; Gene Proteins; Genes; Genetic; Genetic Code; Genetic Structures; Genetic Techniques; Goals; Hand; Human; Hydrogen Bonding; Lysine; Metabolic; Metabolism; Methanosarcina; Methylamines; Methyltransferase; Microbe; Mutagenesis; Mutate; Nature; Organism; Phenotype; Physiological; Proteins; Range; Reaction; Recombinants; Regulator Genes; Reporter Genes; Ribosomes; Role; Selenium; Selenocysteine; Sense Codon; Site-Directed Mutagenesis; Structure; System; Terminator Codon; Testing; Thinking; Time; Transcript; Transfer RNA; Translating; Translations; cis acting element; in vivo; insight; methylamine; microbial; mutant; novel; pyrrolysine; research study; translation factor

DESCRIPTION (provided by applicant): Pyrrolysine, a novel amino acid, was recently found to be encoded by UAG codons in a microbial gene for methylamine metabolism. This is the second example of a genetically encoded non-canonical amino acid since selenocysteine, which 18 years ago was found to be encoded by UGA codons in a microbe. Selenocysteine is now known to be widely distributed and the primary form of selenium in humans. Following this precedent, pyrrolysine holds potential of being more widely distributed and of import in metabolism. Regardless, pyrrolysine will serve as a rare example of how organisms can modulate their genetic code to expand metabolic capabilities, an achievement whose replication holds promise for artificially tailoring novel proteins with biomedical potential. Our long-range goals are to understand the function, biogenesis, and genetic encoding of pyrrolysine. Translation of UAG codons is hypothesized to require a specialized UAG decoding tRNA and a dedicated cognate aminoacyl-tRNA synthetase. The roles of these gene products and others thought to be involved in UAG decoding as pyrrolysine will be investigated using biochemical and genetic approaches. The final structure of pyrrolysine is as yet unknown, and insight into pyrrolysine structure and genetic encoding will be gained by analyzing the UAG encoded residue in protein, the cytosol, and on tRNA. An in vivo system has been developed that will be used to study how UAG functions as a sense rather than a stop codon during UAG translation as pyrrolysine. A similar system will be used for site directed mutagenesis in order to test the hypothesized function of pyrrolysine in enzyme catalysis. Finally, transposon mutagenesis will be used to identify unknown genes with anticipated or unanticipated functions during UAG translation as pyrrolysine.

描述（申请人提供）：吡咯赖氨酸是一种新型氨基酸，最近被发现由甲胺代谢微生物基因中的UAG密码子编码。这是自硒代半胱氨酸以来第二个基因编码的非规范氨基酸的例子，硒代半胱氨酸在 18 年前被发现是由微生物中的 UGA 密码子编码的。现在已知硒代半胱氨酸分布广泛，并且是人类中硒的主要形式。遵循这一先例，吡咯赖氨酸具有更广泛分布和在新陈代谢中重要的潜力。无论如何，吡咯赖氨酸将成为生物体如何调节其遗传密码以扩展代谢能力的罕见例子，这一成就的复制有望人工定制具有生物医学潜力的新型蛋白质。我们的长期目标是了解吡咯赖氨酸的功能、生物发生和遗传编码。假设 UAG 密码子的翻译需要专门的 UAG 解码 tRNA 和专用的同源氨酰基-tRNA 合成酶。这些基因产物和其他被认为参与UAG解码（如吡咯赖氨酸）的基因产物的作用将使用生化和遗传方法进行研究。吡咯赖氨酸的最终结构尚不清楚，通过分析蛋白质、细胞质和 tRNA 中 UAG 编码的残基，可以深入了解吡咯赖氨酸的结构和遗传编码。已经开发出一种体内系统，该系统将用于研究 UAG 在 UAG 翻译为吡咯赖氨酸期间如何作为有义密码子而不是终止密码子发挥作用。类似的系统将用于定点诱变，以测试吡咯赖氨酸在酶催化中的假设功能。最后，转座子诱变将用于鉴定在UAG翻译为吡咯赖氨酸期间具有预期或非预期功能的未知基因。