ASSEMBLY OF TRANSCRIPTION ELONGATION COMPLEXES CONTAINING THE N-PROTEIN OF PHAGE-LAMBDA AND THE ESCHERICHIA-COLI ELONGATION FACTOR-NUSA, FACTOR-NUSB, FACTOR-NUSG, AND FACTOR-S10
ASSEMBLY OF TRANSCRIPTION ELONGATION COMPLEXES CONTAINING THE N-PROTEIN OF PHAGE-LAMBDA AND THE ESCHERICHIA-COLI ELONGATION FACTOR-NUSA, FACTOR-NUSB, FACTOR-NUSG, AND FACTOR-S10
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DOI：
10.1101/gad.5.8.1504
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发表时间：
1991-08-01
影响因子：
10.5
通讯作者：
GREENBLATT, J
中科院分区：
文献类型：
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作者：
MASON, SW;GREENBLATT, J
噬菌体-lambda的转录抗终止蛋白N；大肠杆菌延伸因子NusA、NusB、核糖体蛋白S10和NusG；含有 lambda-nut（N-utilization）位点的 DNA 模板对于在体外高度协作地形成含有所有五种延伸因子的稳定转录复合物来说是必要且充分的。坚果位点 NusA 或 RNA 聚合酶 (RNAP) β 亚基的突变会损害体内的抗终止作用，也会破坏含有抗终止因子的稳定复合物在体外的组装。 RNAP 突变对组装的影响意味着抗终止因子在 RNAP 表面组装。我们之前已经证明 NusA 直接结合转录 RNAP (K)a) 大约 10(7) M-1)； K(a) = 关联常数，我们在此表明 S10 还直接且特异性地与 RNAP 结合，表观 K(a) 为 10(6) M-1。这些观察结果得出了 N 修饰转录复合物有序组装的模型。
The transcription antitermination protein, N, of bacteriophage-lambda; the Escherichia coli elongation factors NusA, NusB, ribosomal protein S10, and NusG; and a DNA template containing a lambda-nut (N-utilization) site are necessary and sufficient for the highly cooperative formation in vitro of stable transcription complexes containing all five elongation factors. Mutations in the nut site, NusA, or the beta-subunit of RNA polymerase (RNAP) that impair antitermination in vivo also abolish the assembly of a stable complex containing the antitermination factors in vitro. The effects of RNAP mutations on assembly imply that the antitermination factors assemble on the surface of RNAP. We have shown previously that NusA binds directly to transcribing RNAP (K)a) approximately 10(7) M-1); K(a) = association constant and we show here that S10 also binds directly and specifically to RNAP with an apparent K(a) of 10(6) M-1. These observations led to a model for the ordered assembly of the N-modified transcription complex.