Zheng H, Wang B, Shaw P, Yeung H
Institute of Genetics Academia Sinica Beijing, China.
Yi Chuan Xue Bao. 1994;21(1):42-51.
A gene encoding Trichosanthin (TCS) was amplified by means of DNA polymerase chain reaction (PCR) and cloned from the genomic DNA of Trichosanthes kirilowii. Its DNA sequence has been determined. Nucleotide sequence analysis indicates that the cloned TCS gene includes 5'-flanking region and the encoding sequence for TCS preproprotein. Comparison of its encoding sequence with the published nucleotide sequences of three TCS genes demonstrates that they have the sequence homologies of 99.20%, 98.74% and 98.64% respectively. Comparing its deduced amino acid sequence with four reported amino acid sequences of TCS demonstrates that they have the sequence homologies of 98.62%, 97.62%, 97.41% and 98.38% respectively. A new TATA-like box sequence was found in the 5'-flanking region of cloned TCS gene. In order to further study the structure, expression, regulating mechanism of TCS gene and the structure-functional relationship of TCS, a series of mutants of TCS gene has been constructed. The expression of these mutants in bacteria and transgenic plant has being studied.
通过DNA聚合酶链式反应（PCR）扩增了编码天花粉蛋白（TCS）的基因，并从栝楼的基因组DNA中克隆得到该基因。已测定其DNA序列。核苷酸序列分析表明，克隆得到的TCS基因包含5'-侧翼区和TCS前体蛋白原的编码序列。将其编码序列与已发表的三个TCS基因的核苷酸序列进行比较，结果表明它们的序列同源性分别为99.20%、98.74%和98.64%。将其推导的氨基酸序列与已报道的四个TCS氨基酸序列进行比较，结果表明它们的序列同源性分别为98.62%、97.62%、97.41%和98.38%。在克隆得到的TCS基因的5'-侧翼区发现了一个新的类似TATA框的序列。为了进一步研究TCS基因的结构、表达、调控机制以及TCS的结构-功能关系，构建了一系列TCS基因的突变体。已对这些突变体在细菌和转基因植物中的表达进行了研究。
