Guild N, Gayle M, Sweeney R, Hollingsworth T, Modeer T, Gold L
Department of Molecular, Cellular and Developmental Biology, University of Colorado, Boulder 80309.
J Mol Biol. 1988 Jan 20;199(2):241-58. doi: 10.1016/0022-2836(88)90311-7.
Transcriptional activation of middle genes in bacteriophage T4 requires the phage-encoded motA protein. Many middle genes are involved in deoxyribonucleotide biosynthesis and phage DNA replication. In the absence of motA, the gene products that are required for DNA synthesis are transcribed from other, upstream promoters. Using primer extension sequencing on RNA templates isolated from T4 motA+ and motA- infected cells, we have characterized 14 motA-dependent transcripts. The T4 middle promoters have a consensus sequence of nine base-pairs, (a/t)(a/t)TGCTT(t/c)A, spaced 11 to 13 nucleotides away from the Escherichia coli--10 consensus sequence, TAnnnT. The motA protein also can act as a transcriptional repressor for at least one early gene. Furthermore, the phage-encoded motA protein can activate in trans a middle promoter resident on a plasmid.
噬菌体T4中基因的转录激活需要噬菌体编码的MotA蛋白。许多中基因参与脱氧核糖核苷酸的生物合成和噬菌体DNA复制。在没有MotA的情况下，DNA合成所需的基因产物从其他上游启动子转录。通过对从T4 motA +和motA-感染细胞中分离的RNA模板进行引物延伸测序，我们鉴定了14种MotA依赖性转录本。T4中启动子具有9个碱基对的共有序列，(a/t)(a/t)TGCTT(t/c)A，与大肠杆菌的-10共有序列TAnnnT相距11至13个核苷酸。MotA蛋白还可以作为至少一个早期基因的转录阻遏物。此外，噬菌体编码的MotA蛋白可以反式激活位于质粒上的中启动子。
