Identification of two new bacteriophage T4 genes that may have roles in transcription and DNA replication.
Identification of two new bacteriophage T4 genes that may have roles in transcription and DNA replication.
复制标题
鉴定出两个可能在转录和 DNA 复制中发挥作用的新噬菌体 T4 基因。
DOI：
10.1128/jvi.61.2.366-374.1987
复制
发表时间：
1987
影响因子：
5.4
通讯作者：
Karam,JD
中科院分区：
文献类型：
--
作者：
Hsu,T;Wei,RX;Dawson,M;Karam,JD
我们已经确定了两个噬菌体T4基因，45.1和45.2，其映射在噬菌体复制基因46（其编码重组起始蛋白）和45（其编码复制和转录所需的双功能蛋白）之间的基因间空间中。基因45.1和45.2的存在以前没有被T4基因组的突变分析所识别。我们克隆了T4基因45.1/45.2片段，测定了其核苷酸序列，并在细菌质粒中高水平表达了其两个阅读框。结果预测gp45.1的分子量为11，400（100个氨基酸），gp45.2的分子量为7，500（62个氨基酸）。我们还确定，在T4感染的大肠杆菌中，基因45.1和45.2与它们的远端邻居基因45通过至少一种转录模式共转录。在一份随附的报告中（K。P.威廉姆斯，G. A. Kassavetis，F. S.埃施和E. P. Geiduschek，J. Virol. 61：600-603，1987），显示基因45.1的产物是所谓的T4诱导的15 K蛋白，一种在噬菌体发育中作用未知的RNA聚合酶结合蛋白。T4基因45.2、45.1和45可能构成宿主RNA聚合酶结合噬菌体蛋白的操纵子。与威廉姆斯等人一起，我们提出术语rpb（RNA聚合酶结合）指T4基因，其产物与宿主RNA聚合酶结合，并将T4基因命名为rpbA。
We have identified two bacteriophage T4 genes, 45.1 and 45.2, that map in the intergenic space between phage replication genes 46 (which encodes a recombination initiation protein) and 45 (which encodes a bifunctional protein required in replication and transcription). The existence of genes 45.1 and 45.2 had not been previously recognized by mutation analysis of the T4 genome. We cloned the T4 gene 45.1/45.2 segment, determined its nucleotide sequence, and expressed its two reading frames at high levels in bacterial plasmids. The results predicted molecular weights of 11,400 (100 amino acids) for gp45.1 and 7,500 (62 amino acids) for gp45.2. We also determined that in T4-infected Escherichia coli, genes 45.1 and 45.2 are cotranscribed with their distal neighbor, gene 45, by at least one mode of transcription. In an accompanying report (K. P. Williams, G. A. Kassavetis, F. S. Esch, and E. P. Geiduschek, J. Virol. 61:600-603, 1987), it is shown that the product of gene 45.1 is the so-called T4-induced 15K protein, an RNA polymerase-binding protein of unknown role in phage development. Possibly, T4 genes 45.2, 45.1, and 45 constitute an operon for host RNA polymerase-binding phage proteins. Jointly with Williams et al., we propose the term rpb (RNA polymerase-binding) to refer to T4 genes whose products bind to the host RNA polymerase and have adopted the name rpbA for T4 gene 45.1.