PULSE DIPOLAR ESR STUDY ON INTERACTION OF HIV-1 NUCLEOCAPSID PROTEIN NCP7

HIV-1 核衣壳蛋白 NCP7 相互作用的脉冲偶极 ESR 研究

• 批准号: 8364052
• 负责人: PETER P BORBAT
• 金额: $ 0.14万
• 依托单位: CORNELL UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2011
• 资助国家: 美国
• 起止时间: 2011-09-01 至 2012-08-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8364052
• 关键词: Antiviral Therapy; Base Pairing; Binding Sites; DNA; DNA Sequence; DNA biosynthesis; Dimerization; Enzymes; Exhibits; Fingers; Funding; Genetic Recombination; Genomics; Grant; HIV-1; Homodimerization; Life Cycle Stages; Mediating; Molecular Chaperones; National Center for Research Resources; Nucleic Acids; Nucleocapsid Proteins; Oligonucleotides; Physiologic pulse; Play; Principal Investigator; Process; RNA; RNA-Directed DNA Polymerase; Reaction; Research; Research Infrastructure; Resources; Response Elements; Reverse Transcription; Source; Structure; Surface; Technology; Transactivation; United States National Institutes of Health; Universities; Viral; Viral Proteins; Zinc Fingers; cost; ds-DNA; flexibility; melting; stem; strong-stop (+) DNA

This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. Primary support for the subproject and the subproject's principal investigator may have been provided by other sources, including other NIH sources. The Total Cost listed for the subproject likely represents the estimated amount of Center infrastructure utilized by the subproject, not direct funding provided by the NCRR grant to the subproject or subproject staff. Prof. Charles P. Scholes from Albany University is actively studying the mechanisms underlying HIV-1 replication. A critical step in HIV-1 replication is reverse transcription of HIV-1 genomic RNA to double-stranded DNA by reverse transcriptase (RT). Two viral proteins, the RT enzyme and a small nucleocapsid protein NCp7, which is well-known nucleic acid chaperone direct this process. At the beginning of the linear DNA synthesis, the newly made minus-strand strong-stop DNA ((-)ssDNA) is transferred to the 3'end of the genomic RNA by means of an hybridization reaction between transactivation response element (TAR) RNA and cTAR DNA sequences. Since both TAR sequences exhibit stable hairpin structures, NCp7 needs to destabilize the TAR structures in order to chaperone their hybridization. NCp7 is characterized by two zinc fingers that plays a key role in HIV-1 life cycle and presents a promising target for an antiviral therapy. It has been shown that NCp7 chaperones the first strand transfer by promoting the annealing of the complementary transactivation response element (TAR) RNA and cTAR DNA stem-loop sequences. This critically relies on NCp7 ability to transiently melt their terminal base pairs. The destabilization activity of NCp7 is mediated by a hydrophobic plateau at the surface of the folded zinc fingers, which restricted the oligonucleotide flexibility. The destabilizing of the TAR and cTAR sequences can be mediated by a single finger motif, while the annealing activity requires the two fingers. NCp7 induces a limited destabilization of the primer binding site (PBS) stem-loops involved in the second strand transfer. However, NCp7 can chaperone their homodimerization, by stabilizing the annealing of their partly self-complementary loops. The propensity of NCp7 to promote the dimerization of partly complementary sequences may favor secondary contacts between viral sequences and thus, recombination and viral diversity. Moreover, NCp7 promotes the second strand transfer, by chaperoning a kissing-loop intermediate, through an extension of the loops and a weakening of the upper base pair of the stem.

该副本是利用资源的众多研究子项目之一 由NIH/NCRR资助的中心赠款提供。对该子弹的主要支持 而且，副投影的主要研究员可能是其他来源提供的 包括其他NIH来源。 列出的总费用可能 代表subproject使用的中心基础架构的估计量， NCRR赠款不直接向子弹或副本人员提供的直接资金。 奥尔巴尼大学的查尔斯·P·斯科尔斯教授正在积极研究HIV-1复制的基础机制。 HIV-1复制的关键步骤是通过逆转录酶（RT）将HIV-1基因组RNA逆转录到双链DNA。两种病毒蛋白，RT酶和一个小核素蛋白NCP7，这是众所周知的核酸伴侣伴侣的指导。在线性DNA合成的开头，通过反式激活响应元件（TAR）RNA和CTAR DNA序列之间的杂交反应，将新制成的负链强力DNA（（ - ）ssDNA（（ - ）ssDNA）转移到基因组RNA的3端。由于两个焦油序列均表现出稳定的发夹结构，因此NCP7需要破坏焦油结构的稳定，以伴有其杂交。 NCP7的特征是两个锌指在HIV-1生命周期中起关键作用，并为抗病毒药疗法提供了有希望的靶标。 已经表明，NCP7伴侣通过促进互补反式激活响应元件（TAR）RNA和CTAR DNA DNA茎环序列的退火而成为第一个链转移。这种关键的依赖于NCP7瞬时融化其末端碱基对的能力。 NCP7的不稳定活性是由折叠锌指表面的疏水性高原介导的，这限制了寡核苷酸的柔韧性。焦油和CTAR序列的不稳定可以由单个手指图案介导，而退火活性则需要两个手指。 NCP7诱导了参与第二链转移的引物结合位点（PBS）茎环的有限不稳定。但是，NCP7可以通过稳定其部分自我平衡循环的退火来伴侣二聚化。 NCP7促进部分互补序列的二聚化的倾向可能有利于病毒序列之间的次要接触，从而有利于重组和病毒多样性。此外，NCP7通过通过环的延伸和茎的上底对的弱化来促进第二链转移，从而促进了接吻环中间人。