CONTROL OF TRANSCRIPTION TERMINATION IN E. COLI

大肠杆菌噬菌体λ染色体上的转录终止被抑制 被病毒N蛋白所感染 阻断N作用的宿主突变（nus，格隆） 也影响细菌染色体上的转录终止。 我们发现 nusB突变体在转录核糖体RNA方面有缺陷， 选择附加的E.大肠杆菌突变体。 我们设计了一个 新的lambda向量来执行此选择，并验证 转录终止在这些突变体中受到影响。 其它大肠改变转录终止的大肠杆菌突变已经被 作为nusAl表型的抑制子分离。 一个这样的抑制器 似乎存在于基因“u”中，该基因编码一个21 kd的蛋白质，位于 一组参与mRNA翻译的基因。 我们希望确定 “u”产品的性质，并询问它是否作为一个链接之间， 转录和翻译。 λ噬菌体不能在E.大肠杆菌溶原性噬菌体 HK022. 这种排除是由于HK022前噬菌体功能Nun，其作用是 作为新的转录终止因子。 Nun与Nus因子相互作用 以引起在λ坚果部位的过早终止。

Transcription termination on the coliphage lambda chromosome is suppressed by the viral N protein. Host mutations which block N action (nus, groN) also affect transcription termination on the bacterial chromosome. We find that nusB mutants are defective in transcribing ribosomal RNA; we are selecting additional E. coli mutants with this defect. We have designed a novel lambda vector to perform this selection, and to verify that transcription termination is affected in these mutants. Other E. coli mutations that alter transcription termination have been isolated as suppressors of the nusAl phenotype. One such suppressor appears to lie in gene "u", which encodes a 21 kd protein and is located in a cluster of genes involved in mRNA translation. We wish to determine the nature of the "u" product, and to ask if it serves as a link between transcription and translation. Bacteriophage lambda does not propagate on E. coli lysogenic for phage HK022. This exclusion is due to a HK022 prophage function, Nun, which acts as a new transcription termination factor. Nun interacts with Nus factors to provoke premature termination at the lambda nut sites.