Autogenous translational operator recognized by bacteriophage T4 DNA polymerase.
Autogenous translational operator recognized by bacteriophage T4 DNA polymerase.
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DOI：
10.1016/s0022-2836(05)80261-x
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发表时间：
1990-06
影响因子：
5.6
通讯作者：
C. Tuerk;S. Eddy;D. Parma;L. Gold
中科院分区：
文献类型：
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作者：
C. Tuerk;S. Eddy;D. Parma;L. Gold
T4噬菌体DNA聚合酶的合成受自身调节。这种蛋白(Gp43)是基因43的产物，它与其核糖体结合部位重叠的mRNA片段结合，从而阻止翻译。我们测得gp43-算符相互作用的Kd为1·0×10-−-9M。Gp43结合的最小操纵子序列由36个核苷酸组成，包括一个发夹(包含一个5碱基对螺旋和一个8个核苷酸环)和一个单链片段，该片段包含核糖体结合位点的Shine-Dalgarno序列。在远亲噬菌体RB69中，其DNA聚合酶基因的核糖体结合位点上的发夹和环状序列有显着的保守。我们已经构建了在体内过量生产gp43的噬菌体操作员突变体，但在活体复制率和噬菌体产量方面没有变化。我们提供的数据表明，复制和自动调节功能是这种聚合酶的相互排斥的活动，并提出了一个将自动调节与复制需求联系起来的gp43合成模型。
The synthesis of the DNA polymerase of bacteriophage T4 is autogenously regulated. This protein (gp43), the product of gene43, binds to a segment of its mRNA that overlaps its ribosome binding site, and thereby blocks translation. We have determined theKdof the gp43-operator interaction to be 1·0 × 10−9M. The minimum operator sequence to which gp43 binds consists of 36 nucleotides that include a hairpin (containing a 5 base-pair helix and an 8 nucleotide loop) and a single-stranded segment that contains the Shine-Dalgarno sequence of the ribosome binding site. In the distantly related bacteriophage RB69 there is a remarkable conservation of this hairpin and loop sequence at the ribosome binding site of its DNA polymerase gene. We have constructed phage operator mutants that overproduce gp43in vivo, yet are unchanged forin vivoreplication rates and phage yield. We present data that show that the replicative and autoregulatory functions are mutually exclusive activities of this polymerase, and suggest a model for gp43 synthesis that links autoregulation to replicative demand.