Fisher R, Yanofsky C
Nucleic Acids Res. 1984 Apr 11;12(7):3295-302. doi: 10.1093/nar/12.7.3295.
DNA oligomers were synthesized that are perfectly complementary to different segments of the tryptophan (trp) operon leader transcript. These 15 nucleotide long oligomers were used as probes of the involvement of transcript secondary structures in two processes: transcription pausing at the pause site located near base pair 90 in the leader region, and transcription termination at the attenuator. The 15-mers were complementary to the four segments of the trp leader transcript which have been shown to form the alternative secondary structures that are believed to be responsible for pausing, termination, and antitermination. Oligomers complementary to RNA segments 1 and 3 relieved termination while the 15-mer complementary to RNA segment 1 relieved pausing. 15-mers complementary to segment 2 had no effect on pausing and the oligomer complementary to segment 4 had virtually no effect on termination.
合成了与色氨酸(trp)操纵子前导转录本不同片段完全互补的DNA寡聚物。这些15个核苷酸长的寡聚物被用作转录本二级结构参与两个过程的探针:在位于前导区碱基对90附近的暂停位点处的转录暂停,以及在衰减子处的转录终止。这15聚体与trp前导转录本的四个片段互补,这四个片段已被证明能形成交替的二级结构,据信这些结构负责暂停、终止和抗终止。与RNA片段1和3互补的寡聚物可缓解终止,而与RNA片段1互补的15聚体可缓解暂停。与片段2互补的15聚体对暂停没有影响,与片段4互补的寡聚物对终止几乎没有影响。