KING POST-DOC/TECHNICIAN SUPPORT

这个子项目是许多研究子项目中的一个 由NIH/NCRR资助的中心赠款提供的资源。子项目和 研究者（PI）可能从另一个NIH来源获得主要资金， 因此可以在其他CRISP条目中表示。所列机构为 研究中心，而研究中心不一定是研究者所在的机构。 本项目的目标是了解最初在噬菌体HK 022中发现的转录延伸控制的独特机制。λ噬菌体家族的大多数成员使用噬菌体编码的蛋白质通过抑制转录终止来促进早期基因表达。HK 022不编码抗终止蛋白，而是依赖于新生转录物中的位点与RNA聚合酶的直接相互作用。具体的假设是，基于RNA的抗终止剂的活性取决于RNA聚合酶对新生转录物中的序列和结构信息的识别。这一假设基于先前的研究，1）已经表明，破坏RNA中碱基配对的突变减少了抗终止作用，重建碱基配对的二次突变恢复了终止子读段，2）互换抗终止子RNA的片段显著影响活性，3）RNA介导的抗终止作用被E β prime亚基中的突变阻断。coli RNA聚合酶。本提案的目标是确定所需的序列和结构元件的RNA为基础的抗终止剂。具体目标是：1）鉴定类胡萝卜素中抗终止子RNA的其他实例; 2）使用体内、体外和计算机模拟方法来确定新鉴定的抗终止子RNA的结构和功能重要特征; 3）完成两个具有基于RNA的抗终止子的新噬菌体基因组的注释。在HK 022中发现的抗终止子序列提供了通过直接修饰转录装置来控制基因表达的RNA的独特实例。不寻常的基因调控模式是药物设计的潜在目标。因此，更好地了解抗终止子RNA及其通过RNA聚合酶的识别可能有助于发现或开发能够改变毒力基因表达的治疗剂，从而减轻疾病过程。

This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. The goal of this project is to understand a unique mechanism of transcription elongation control originally discovered in the bacteriophage HK022. Most members of the lambda phage family use phage-encoded proteins to promote early gene expression by suppressing transcription termination. HK022 does not encode an antitermination protein but relies instead on the direct interaction of sites in the nascent transcript with RNA polymerase. The specific hypothesis is that the activity of RNA-based antiterminators depends upon the recognition of sequence and structural information in the nascent transcript by RNA polymerase. This hypothesis is based upon previous studies that 1) have shown that mutations that disrupt base pairing in the RNA reduce antitermination and secondary mutations that re-establish base pairing restore terminator read through 2) interchanging segments of antiterminator RNAs drastically affects activity, and 3) RNA-mediated antitermination is blocked by mutations in the beta prime subunit of E. coli RNA polymerase. The goal of this proposal is to identify the required sequence and structural elements of RNA based antiterminators. The specific aims are: 1) to identify additional examples of antiterminator RNAs in lambdoid phages; 2) to use in vivo, in vitro and in silico approaches to determine the structurally and functionally important features of the newly identified antiterminator RNAs; and 3) to complete the annotation of two new phage genomes that possess RNA-based antiterminators. The antiterminator sequences discovered in HK022 provide unique examples of RNAs that control gene expression by directly modifying the transcription apparatus. Unusual modes of gene regulation are potential targets for drug design. Therefore, a better understanding of antiterminator RNAs and their recognition by RNA polymerase may facilitate the discovery or development of therapeutic agents capable of altering the expression of virulence genes and thus attenuating disease processes.