IDENTIFYING THE PATH OF THE RNA PRIMER AROUND A SIMPLE RNA POLYMERASE

这个子项目是利用资源的许多研究子项目之一 由NIH/NCRR资助的中心拨款提供。子项目的主要支持 子项目的主要研究者可能是由其他来源提供的， 包括其它NIH来源。 列出的子项目总成本可能 表示子项目使用的中心基础设施的估计数量， NCRR赠款不直接向子项目或子项目工作人员提供资金。 牛痘病毒多聚腺苷酸聚合酶（VP 55）是已知的唯一相对于其RNA引物移位的RNA聚合酶，这引起了一个悖论：聚合酶或引物哪个更灵活？该蛋白质有两种已知的作用模式，即进行性合成的30 nt的尾巴，并作为异源二聚体与其持续合成因子（VP 39），半进行性合成的200？300新台币的尾巴。过去的合作研究已经产生了VP 39和VP 55-VP 39异源二聚体的晶体结构。最重要的，但缺乏的信息是异源二聚体引物复合物的结构理解。通过使用同事的光束时间，格申实验室的全职晶体学家在寻找聚合酶表面短RNA片段的结合位点方面取得了显着进展。虽然这是一个开创性的，原始的工作聚（A）聚合酶，3小时的光束时间每2个月提供了不充分的进展，在这个NIH资助的工作，以确保赠款更新。射束时间是主要的瓶颈，因此，目前的要求，个人，定期射束时间的结晶工作。

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. Vaccinia virus poly(A) polymerase (VP55) is the only RNA polymerase known to translocate with respect to its RNA primer, raising a paradox: Which is more flexible: The polymerase or the primer? The protein has two known modes of action, namely the processive synthesis of 30 nt tails and, as a heterodimer with its processivity factor (VP39), the semi-processive synthesis of 200 ? 300 nt tails. Past, collaborative studies, have yielded crystal structures for VP39, and for the VP55-VP39 heterodimer. The most important, yet absent information is a structural understanding of the heterodimer-primer complex. By using the beam time of a colleague, a full-time crystallographer in the Gershon lab has progressed markedly in finding binding sites for short RNA segments on the polymerase surface. Although this is ground-breaking, original work for a poly(A) polymerase, 3 hours of beam time every 2 months provides inadequate progress in this NIH-funded work to ensure grant renewal. Beam time is the major bottleneck, hence the current request for individual, regular beam time for this crystallographic work.