DNA sequence of Rhizobium trifolii nodulation genes reveals a reiterated and potentially regulatory sequence preceding nodABC and nodFE.
DNA sequence of Rhizobium trifolii nodulation genes reveals a reiterated and potentially regulatory sequence preceding nodABC and nodFE.
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三叶根瘤菌结瘤基因的 DNA 序列揭示了 nodABC 和 nodFE 之前的重复且潜在的调控序列。
DOI：
10.1093/nar/14.7.2891
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发表时间：
1986
影响因子：
14.9
通讯作者：
J. Watson
中科院分区：
文献类型：
--
作者：
P. Schofield;J. Watson
三叶草宿主特异性结瘤所需的三叶根瘤菌结瘤基因位于 14 kb 的 Sym（共生）质粒 DNA 上。对该区域 3.7 kb 部分的核苷酸序列的分析揭示了与 nodABCDEF 基因相对应的开放阅读框。 DNA测序技术使用Tn5内的引物延伸，已被用来确定nod基因内Tn5突变的精确位置，以及相应突变体的表型与其定位位置相关。预测的 nodA 和 nodB 基因重叠四个核苷酸，而 nod F 和 nodE 基因重叠一个核苷酸，表明翻译偶联可以确保等摩尔量的这些基因产物的合成。 nodABC 和 nodFE 基因构成独立的转录单位，每个基因前面都有一个保守的 76 bp 序列，该序列可能参与这些基因表达的调节。
The Rhizobium trifolii nod genes required for host-specific nodulation of clovers are located on 14 kb of Sym (symbiotic) plasmid DNA. Analysis of the nucleotide sequence of a 3.7 kb portion of this region has revealed open reading frames corresponding to the nodABCDEF genes. A DNA sequencing technique, using primer extension from within Tn5, has been used to determine the precise locations of Tn5 mutations within the nod genes and the phenotypes of the corresponding mutants correlate with their mapped locations. The predicted nodA and nodB genes overlap by four nucleotides and the nod F and nodE genes overlap by a single nucleotide, suggesting that translational coupling may ensure the synthesis of equimolar amounts of these gene products. The nodABC and nodFE genes constitute separate transcriptional units and each is preceded by a conserved 76-bp sequence which may be involved in the regulation of expression of these genes.