Mauro V P, Nguyen T, Katinakis P, Verma D P
Nucleic Acids Res. 1985 Jan 11;13(1):239-49. doi: 10.1093/nar/13.1.239.
The nodulin-23 gene of soybean is one of the most abundantly transcribed genes induced during symbiosis with Rhizobium. Using a plasmid (pNod25) from a nodule cDNA library, we have isolated the nodulin-23 gene from a soybean genomic library. Nucleotide sequence analysis of the cDNA and of the genomic clone indicated that the coding region of this gene is 669 bp long and is interrupted by a single intron of about 530 bp. The deduced protein sequence suggests that nodulin-23 may have a signal sequence. The 5'-flanking sequence of two other nodulin genes, nodulin-24 encoding for a membrane polypeptide and one of the leghemoglobin genes (LbC3), were obtained. Comparison of these sequences revealed three conserved regions, one of which, an octanucleotide (GTTTCCCT), has 100% homology. The conserved sequences are arranged in a unique fashion and have a spatial organization with respect to order and position, which may suggest a potential regulatory role in controlling the expression of nodulin and leghemoglobin genes during symbiosis.
大豆的根瘤菌素-23基因是在与根瘤菌共生期间诱导转录最丰富的基因之一。利用来自根瘤cDNA文库的质粒(pNod25),我们从大豆基因组文库中分离出了根瘤菌素-23基因。对cDNA和基因组克隆的核苷酸序列分析表明,该基因的编码区长度为669 bp,被一个约530 bp的单一内含子打断。推导的蛋白质序列表明根瘤菌素-23可能有一个信号序列。获得了另外两个根瘤菌素基因的5'侧翼序列,一个是编码膜多肽的根瘤菌素-24,另一个是豆血红蛋白基因之一(LbC3)。对这些序列的比较揭示了三个保守区域,其中一个八核苷酸(GTTTCCCT)具有100%的同源性。保守序列以独特的方式排列,并且在顺序和位置方面具有空间组织,这可能表明在共生期间控制根瘤菌素和豆血红蛋白基因表达方面具有潜在的调节作用。