Biosynthesis of hypermodified gaunosines.

超修饰鸟苷的生物合成。

• 批准号: 7937367
• 负责人: Valerie A de Crecy-Lagard
• 金额: $ 7.5万
• 依托单位: UNIVERSITY OF FLORIDA
• 依托单位国家: 美国
• 财政年份: 2009
• 资助国家: 美国
• 起止时间: 2009-09-30 至 2010-08-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7937367
• 关键词: 7-deazaguanine; 7-deazaguanosine; Amino Acids; Anabolism; Anti-Bacterial Agents; Archaea; Bacillus subtilis; Bacteria; Biochemical; Biochemistry; Bioinformatics; Biological Factors; Biological Process; Biology; Biopterin; Cell physiology; Chemicals; Chemistry; Classification; Codon Nucleotides; Comparative Genomic Analysis; Complex; DNA Sequence; Enzyme Gene; Enzymes; Eukaryota; Event; Evolution; Exhibits; Family; Folate; GTP Cyclohydrolase; GTP Cyclohydrolase I; Genes; Genetic; Genetic Code; Genome; Genomics; Guanosine Triphosphate; In Vitro; Link; Metabolism; Methods; Microbial Physiology; Modification; Molecular; Nitriles; Nucleic Acids; Nucleoside Q; Nucleosides; Organism; Orthologous Gene; Oxidoreductase; Pathway interactions; Pharmacologic Substance; Physiological; Positioning Attribute; Process; Prokaryotic Cells; RNA; Role; Streptomyces; Structure; Testing; Toyocamycin; Transfer RNA; Translations; Tubercidin; Validation; Work; Workplace; antineoplastic antibiotics; archaeosine; comparative; functional/structural genomics; gene conservation; genome sequencing; in vivo; insight; interest; microorganism; novel; pathogen; sangivamycin; stem; tumor

Project Summary. The post-transcriptional processing of transfer RNA (tRNA) involves a number of functionally distinct events essential for tRNA maturation. The phenomenon of nucleoside modification is perhaps the most remarkable of these events, and results in a wealth of structural changes to the canonical nucleosides. Two of the most remarkable modified nucleosides found in tRNA are the 7-deazaguanosine derivatives queuosine and archaeosine, which have putative roles in translation and RNA stabilization, respectively. While evolutionarily related, these nucleosides are segregated within separate Domains; queuosine is ubiquitous among Bacteria and Eukarya, while archaeosine is only present in the Archaea. The 7-deazapurine structure in general is widespread in biology, where it is found in a variety of natural products such as the antitumor antibiotics toyocamycin,sangivamycin, and tubercidin from Streptomyces. The biosynthetic pathways to these deazapurines are poorly understood, a fact that has stymied functional studies. The availability of hundreds of sequenced genomes now allows the identification of genes and pathways using a comparative genomics approach. This approach was used to discover five new enzymes in the de novo biosynthesis of queuosine and archaeosine, and potentially of other 7-deazapurine metabolites. Notably, this pathway is limited to prokaryotes, and some of these newly discovered enzymes appear to catalyze chemistry unprecedented in biology. The long-term objectives of this project are to , elucidate the biosynthesis and metabolism of 7-deazapurines in prokaryotes. The specific aims of this proposal are 1) to elucidate the role of these new enzymes in the early steps in the queuosine and archaeosine biosynthetic pathways leading to the formation of the common precursor 7-cyano-7- deazaguanine, 2) to initiate studies into the broader metabolism of these modified nucleosides, and 3) to investigate the mechanism and structure of one of these enzymes, a novel nitrile oxidoreductase. This proposal brings an ensemble of bioinformatic, genetic, biochemical, and chemical approaches to the problem of elucidating the biosynthesis of 7-deazaguanine modified nucleosides. The study of this new pathway and the constituent enzymes will provide unprecedented access to elucidating the biology of 7-deazapurine metabolism and its manipulation. Relevance. The pathway to 7-deazapurines is unique to microorganisms, and many of the constitute enzymes are potentially new antibacterial targets. Furthermore, one of the enzymes is a novel nitrile oxidoreductase that may have applications in industrial biocatalysis.

项目摘要。转移RNA（TRNA）的转录后处理涉及多个 功能上不同的事件对于tRNA成熟至关重要。核苷修饰的现象是 也许是这些事件中最杰出的事件，并导致规范的大量结构变化 核苷。在tRNA中发现的两个最显着的修饰核苷是7-二氮烷糖苷 衍生物queuosine和考古，在翻译和RNA稳定中具有假定的作用， 分别。虽然在进化上相关，但这些核苷在单独的结构域中被隔离。 在细菌和真核生中，queuosine无处不在，而古细菌仅存在古细菌。这 总体上，7-二唑啉结构在生物学中广泛存在，在各种天然产品中都可以找到它 例如链霉菌的抗肿瘤抗生素Toyocamycin，sangivamycin和tubercidin。这 这些脱氮嘌呤的生物合成途径知之甚少，这一事实令人困惑 研究。现在，数百个测序基因组的可用性允许鉴定基因和 使用比较基因组学方法的途径。这种方法用于发现五种新酶 在queuosine和古岛的新生生物合成中，可能是其他7-二氮嗪的生物合成 代谢物。值得注意的是，这种途径仅限于原核生物，其中一些新发现的酶 在生物学中似乎是史无前例的化学。该项目的长期目标是 阐明原核生物中7-二氮杂的生物合成和代谢。这个特定的目的 提案是1）阐明这些新酶在Queuosine的早期步骤中的作用 考古生物合成途径，导致形成共同前体7-氰基-7-- Deazaguanine，2）启动研究这些修饰的核苷的更广泛代谢，3） 研究这些酶之一，一种新型硝酸氧化还原酶的机理和结构。这 提案带来了生物信息学，遗传，生化和化学方法的合奏 阐明7-二瓜氨酸修饰的核苷的生物合成。对这一新途径的研究 组成酶将为阐明7-二氮嗪的生物学提供前所未有的访问 代谢及其操纵。 关联。通往7-二氮嘌呤的途径是微生物独有的，许多构成 酶是潜在的新抗菌靶标。此外，其中一种酶是一种新颖的硝酸 可能在工业生物催化中应用的氧化还原酶。