DNA sequence of a T4 transfer RNA gene cluster.
DNA sequence of a T4 transfer RNA gene cluster.
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T4 转移 RNA 基因簇的 DNA 序列。
DOI：
10.1016/0022-2836(80)90136-9
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发表时间：
1980
影响因子：
5.6
通讯作者：
J. Abelson
中科院分区：
文献类型：
--
作者：
K. Fukada;J. Abelson
噬菌体T4编码8个tRNA，其基因紧密聚集在genese和57之间。转移RNA基因的聚集表明这些tRNA是在单个转录单元中合成的。体外转录实验和体内使用 λ-T4 杂交体的实验支持了这一观点并定位了 T4 tRNA 启动子。T4 tRNA 加工部分的详细生化途径是已知的。 3'端的成熟先于5'端的成熟，并且三个二聚体前体的3'端在tRNA核苷酸转移酶和核糖核酸酶BN的作用下以不同的方式成熟。所有 T4 tRNA 的 5' 成熟都需要 RNAase P。单体和二聚体前体在没有 RNAase P 的情况下积累。然而，人们对这些单体和二聚体前体是如何从其初级转录物合成的了解甚少。使用携带 tRNA 基因的 λ-T4 杂交体和 tRNA 基因簇的精细限制性图谱，我们确定了 tRNA 基因簇的 DNA 序列，希望对基因组织的理解可以提示 tRNA 是如何从其初级转录物加工而来的。 tRNA 基因簇的 DNA 序列表明单体和二聚体前体是通过单次核酸内切裂解从其初级转录物产生的。我们提出了一个通过预测这种核酸内切酶（或多种核酸内切酶）来实现 T4 tRNA 成熟的模型。宿主体内存在拟议的核酸内切活性。该模型回答了有关加工的各种问题，并揭示了 T4 tRNA 加工的独特特征。
Bacteriophage T4 codes for eight tRNAs, whose genes are tightly clustered between geneseand 57. The clustering of the transfer RNA genes suggested that these tRNAs are synthesized in a single transcriptional unit. Transcriptional experimentsin vitroand experiments using the λ-T4 hybridin vivohave supported this notion and located a T4 tRNA promoter.Detailed biochemical pathways of parts of the T4 tRNA processing are known. Maturation of the 3′ end precedes that of the 5′ end, and the 3′ ends of three dimeric precursors are matured in different ways by tRNA nucleotidyltransferase and ribonuclease BN. All T4 tRNAs require RNAase P for their 5′ maturation. Monomeric and dimeric precursors accumulate in the absence of RNAase P.How these monomeric and dimeric precursors are synthesized from their primary transcript, however, is poorly understood. Using the λ-T4 hybrid, carrying tRNA genes, and a fine restriction map of the tRNA gene cluster, we have determined the DNA sequence of the tRNA gene cluster, hoping that understanding of gene organization may suggest how the tRNAs are processed from their primary transcript. The DNA sequence of the tRNA gene cluster indicates that the monomeric and dimeric precursors are generated from their primary transcript by single endonucleolytic cleavages. We propose a model for the maturation of T4 tRNAs by predicting such an endonuclease (or endonucleases). The proposed endonucleolytic activities exist in the host. This model answers various questions about processing and reveals the unique features of T4 tRNA processing.