Genes coding for the major tuberous root protein of sweet potato: Identification of putative regulatory sequence in the 5′ upstream region
Genes coding for the major tuberous root protein of sweet potato: Identification of putative regulatory sequence in the 5′ upstream region
复制标题
编码甘薯主要块根蛋白的基因：鉴定 5 上游区域的推定调控序列
作者：
T. Hattori;K. Nakamura
本文报道了编码甘薯块根主要可溶性蛋白的多基因家族中孢子素A基因和B基因gSPO-A1和gSPO-B1的分离和鉴定。测定了这两个基因及其5′和3′侧区的核苷酸序列。通过S1核酸酶作图确定转录起始位点。与孢素A和B的全长cdna序列比较发现，这些基因不含内含子。通过点阵图分析序列比较发现，gSPO-A1和gSPO-B1的5 '侧区同源性仅延伸到转录起始位点上游45 bp处，其中包括一致的TATA box序列。该区域的序列在孢素相关基因gSPO-X1中也保守，该基因似乎在块根中不表达。gSPO-A1和gSPO-B1的5′侧序列存在28 ~ 29 bp和19 ~ 22 bp的短序列块，而gSPO-X1则不存在。19-22 bp序列在gSPO-A1中重复2次，在gSPO-B1中重复4次。这些保守的序列片段可能在它们的表达中起调控作用。
The isolation and characterization is described of sporamin A and B genes, gSPO-A1 and gSPO-B1, respectively, which are members of two distinct subfamilies of the multigene family encoding the major soluble protein of sweet potato tuberous root. The nucleotide sequences of the two genes along with the 5′ and 3′ flanking regions were determined. The transcriptional start sites were determined by S1 nuclease mapping. Comparison of the sequences with those of the full-length cDNAs for sporamin A and B reveals that these genes contain no introns. Sequence comparison by dot matrix plot analysis shows that homology of the 5′ flanking regions between gSPO-A1 and gSPO-B1 extends only to 45 bp upstream of the transcription start site, which includes the consensus TATA box sequence. The sequence of this region is also conserved in the sporamin-related gene, gSPO-X1, which dose not seem to be expressed in the tuberous root. The sequences further upstream diverge extensively, but two short sequence blocks of 28 to 29 bp and 19 to 22 bp are found in the 5′ flanking sequence of gSPO-A1 and gSPO-B1 but not in gSPO-X1. The 19–22 bp sequence block is repeated twice in gSPO-A1 and four times in gSPO-B1. These conserved sequence blocks may play regulatory roles in their expression.