Bend induced by the phage phi 29 transcriptional activator in the viral late promoter is required for activation.
Bend induced by the phage phi 29 transcriptional activator in the viral late promoter is required for activation.
复制标题
病毒晚期启动子中的噬菌体 phi 29 转录激活因子诱导的弯曲是激活所必需的。
DOI：
10.1016/0022-2836(90)90072-t
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发表时间：
1990
影响因子：
5.6
通讯作者：
Salas,M
中科院分区：
文献类型：
--
作者：
Rojo,F;Zaballos,A;Salas,M
枯草芽孢杆菌φ29晚期A3启动子的转录起始需要病毒蛋白p4，一种转录激活因子。蛋白质p4与A3启动子的一个区域结合，该区域位于相对于转录起始位点的-50和-100个核苷酸之间，呈现序列导向的曲率。当蛋白质p4与启动子结合时，这种曲率增强。在蛋白质p4的羧基端的缺失突变体的数量已经构建和他们的行为作为晚期A3启动子的转录激活因子进行了研究。通过凝胶阻滞、DNA酶I足迹法、甲基化干扰和环状排列试验分析了这些缺失突变体与晚期A3启动子的结合。结果表明，蛋白质p4的最后12个氨基酸残基，其中6个是带正电荷的，虽然不参与启动子的特异性识别负责蛋白质p4在其结合位点诱导的部分弯曲。证据表明，充分诱导这种曲率是需要的转录激活过程。提出了蛋白质p4与A3启动子相互作用的模型，其中弯曲的诱导分两步进行：首先，蛋白质p4的两个单体与反向识别序列结合，随后它们之间的相互作用在这些序列之间产生弯曲;第二，蛋白质P4的高碱性羧基末端建立了非-与DNA骨架的特异性静电相互作用在蛋白质p4结合区的两端诱导弯曲。
Transcription initiation from theBacillus subtilisphage φ29 late A3 promoter requires the viral protein p4, a transcriptional activator. Protein p4 binds to a region of the A3 promoter, located between nucleotides −50 and −100 relative to the transcription start site, that presents a sequence-directed curvature. This curvature is enhanced when protein p4 binds to the promoter. A number of deletion mutants at the carboxyl end of protein p4 have been constructed and their behavior as transcriptional activators of the late A3 promoter has been investigated. The binding of these deletion mutants to the late A3 promoter has been analyzed by gel retardation, DNase I footprinting, methylation interference and circular permutation assays. The results suggest that the last 12 amino acid residues of protein p4, six of which are positively charged, although not involved in the specific recognition of the promoter are responsible for part of the bend induced by protein p4 in its binding site. Evidence is presented which suggests that full induction of this curvature is needed for the transcription activation process. A model is proposed for protein p4 interaction with the A3 promoter, in which the bend is induced in two steps: first, two monomers of protein p4 bind to the inverted recognition sequences, subsequent interaction between them generating a bend between these sequences; second, the highly basic carboxyl terminus of protein p4 establishes non-specific electrostatic interactions with the DNA backbone inducing a bend at both ends of the protein p4 binding region.