Biosynthesis of hypermodified gaunosines.

超修饰鸟苷的生物合成。

• 批准号: 7579131
• 负责人: Valerie A de Crecy-Lagard
• 金额: $ 23.82万
• 依托单位: UNIVERSITY OF FLORIDA
• 依托单位国家: 美国
• 财政年份: 2006
• 资助国家: 美国
• 起止时间: 2006-03-02 至 2011-02-28
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7579131
• 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。转运RNA（tRNA）的转录后加工涉及许多转录因子。 tRNA成熟所必需的功能上不同的事件。核苷修饰的现象是 也许是最显着的这些事件，并在丰富的结构变化的结果，规范 核苷在tRNA中发现的两种最显著的修饰核苷是7-脱氮鸟苷 衍生物古苷和古苷，它们在翻译和RNA稳定中具有假定的作用， 分别虽然在进化上相关，但这些核苷在不同的结构域中分离; 古生物素普遍存在于细菌和真核生物中，而古生物素仅存在于真核生物中。的 7-脱氮嘌呤结构一般在生物学中广泛存在，在各种天然产物中发现 如来自链霉菌属的抗肿瘤抗生素丰卡霉素、桑伐霉素和杀结核菌素。的 对这些脱氮嘌呤的生物合成途径知之甚少，这一事实阻碍了功能性的 问题研究数百个已测序的基因组的可用性现在允许识别基因， 使用比较基因组学方法的途径。这种方法被用来发现五种新的酶 在古生苷和古生苷的从头生物合成中，以及潜在的其他7-脱氮嘌呤的从头生物合成中 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 似乎催化了生物学中前所未有的化学反应。该项目的长期目标是， 阐明原核生物中7-脱氮嘌呤的生物合成和代谢。具体目标是 建议是：1）阐明这些新酶在肌苷合成的早期步骤中的作用， 古菌素生物合成途径导致形成共同的前体7-氰基-7- 脱氮鸟嘌呤，2）启动对这些修饰核苷的更广泛代谢的研究，以及3） 研究这些酶之一，一种新的腈氧化还原酶的机制和结构。这 该提案将生物信息学、遗传学、生物化学和化学方法结合起来解决这个问题 阐明7-脱氮鸟嘌呤修饰核苷的生物合成。对这一新途径的研究， 组成酶将为阐明7-脱氮嘌呤的生物学提供前所未有的途径 代谢及其操纵。 本案无关7-脱氮嘌呤的途径是微生物所特有的，并且许多组成7-脱氮嘌呤的化合物都是由7-脱氮嘌呤所组成。 酶是潜在的新抗菌靶标。此外，其中一种酶是一种新的腈 可能在工业生物催化中有应用的氧化还原酶。