来自RNA聚合酶β'亚基的卷曲螺旋通过σ（70）变构诱导选择性非模板链结合。

A coiled-coil from the RNA polymerase beta' subunit allosterically induces selective nontemplate strand binding by sigma(70).

作者信息

Young B A, Anthony L C, Gruber T M, Arthur T M, Heyduk E, Lu C Z, Sharp M M, Heyduk T, Burgess R R, Gross C A

机构信息

Department of Biochemistry and Biophysics, University of California, San Francisco, San Francisco, CA 94143, USA.

出版信息

Cell. 2001 Jun 29;105(7):935-44. doi: 10.1016/s0092-8674(01)00398-1.

DOI:10.1016/s0092-8674(01)00398-1

PMID:11439189

Abstract

For transcription to initiate, RNA polymerase must recognize and melt promoters. Selective binding to the nontemplate strand of the -10 region of the promoter is central to this process. We show that a 48 amino acid (aa) coiled-coil from the beta' subunit (aa 262--309) induces sigma(70) to perform this function almost as efficiently as core RNA polymerase itself. We provide evidence that interaction between the beta' coiled-coil and region 2.2 of sigma(70) promotes an allosteric transition that allows sigma(70) to selectively recognize the nontemplate strand. As the beta' 262--309 peptide can function with the previously crystallized portion of sigma(70), nontemplate recognition can be reconstituted with only 47 kDa, or 1/10 of holoenzyme.

摘要

为了启动转录，RNA聚合酶必须识别并解链启动子。选择性结合到启动子-10区的非模板链是这一过程的核心。我们发现，β'亚基的一段48个氨基酸（aa）的卷曲螺旋（aa 262 - 309）能诱导σ⁷⁰几乎像核心RNA聚合酶自身一样高效地执行此功能。我们提供的证据表明，β'卷曲螺旋与σ⁷⁰的2.2区之间的相互作用促进了变构转变，使σ⁷⁰能够选择性地识别非模板链。由于β' 262 - 309肽可以与σ⁷⁰先前结晶的部分发挥作用，因此仅用47 kDa（全酶的1/10）就能重建非模板识别。