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: 6868249
• 负责人: JOSEPH Adrian KRZYCKI
• 金额: $ 27.56万
• 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/6868249
• 关键词: Archaea; acylation; aminoacid analog; aminoacid metabolism; aminoacid tRNA ligase; catalyst; chemical structure; genetic manipulation; genetic regulatory element; genetic translation; lysine; mass spectrometry; methyltransferase; microorganism genetics; microorganism metabolism; nucleic acid sequence; site directed mutagenesis; transfer RNA; transposon /insertion element

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（由申请人提供）：最近发现，一种新型氨基酸的吡咯氨酸是由UAG密码子在微生物基因中编码的甲胺代谢。这是自硒代半胱氨酸以来的遗传编码的非经典氨基酸的第二个例子，该硒是18年前被Microbe中的UGA密码子编码的。现在已知硒代半胱氨酸分布广泛，是人类硒的主要形式。遵循这一先例，吡咯氨氨酸具有更广泛的分布和代谢进口的潜力。无论如何，吡咯氨氨酸将是生物如何调节其遗传代码以扩展代谢能力的罕见例子，该成就的复制有望有望人工调整具有生物医学潜力的新型蛋白质。我们的远距离目标是了解吡咯氨酸的功能，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和专用的同源氨基酰基-TRNA合成酶。这些基因产物的作用以及其他被认为与UAG解码有关的作用将使用生化和遗传方法研究。吡咯氨氨酸的最终结构尚不清楚，并且可以通过分析蛋白质，细胞质和tRNA中的UAG编码的残基来获得对吡咯氨酶结构和遗传编码的见解。已经开发了一个体内系统，该系统将用于研究UAG在UAG翻译中以吡咯氨氨酸的含义而不是终止密码子的功能。类似的系统将用于定位诱变，以测试吡咯氨氨酸在酶催化中的假设功能。最后，转座子诱变将用于鉴定UAG翻译过程中具有预期或意外功能的未知基因为吡咯氨碱。