| 摘要: |
| 以中华齿米虾(Neocaridina denticulata sinensis)基因组DNA为模板,根据胰蛋白酶基因保守序列设计简并引物,利用PCR技术获得一个基因。序列分析表明此基因与已报道的凡纳滨对虾 (Litopenaeus vannamei)胰蛋白酶基因有较高的相似度,序列中包含一个内含子和两个不完整的外显子,编码182个氨基酸残基。该氨基酸序列与凡纳滨对虾胰蛋白酶 氨基酸序列的相似度为83.5%;含有胰蛋白酶所特有的His、Asp和Ser组成的活性三联体、决定胰蛋白酶底物专一性的Asp、底物结合部位的G1y 残基。综合分析认定该基因为胰蛋白酶基因片断。将其氨基酸序列与报道的其他动物胰蛋白酶氨基酸序列进行了系统进化分析。系统进化分析的结果与现有以表型特 征为依据的虾分类结果是一致的。 |
| 关键词: 中华齿米虾(Neocaridina denticulata sinensis) 胰蛋白酶 基因 系统进化分析 |
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| Study on the trypsin gene from Neocaridina denticulata sinensis |
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| Abstract: |
| According to the conserved domain of some trypsin genes reported in the Genbank, a pair of degenerate primers were designed and synthesized. Using genomic DNA of Neocaridina denticulata sinensis as a template polymerase chain reaction(PCR) was performed to clone a trypsin gene. Analysis of DNA sequence showed that the sequence was highly homologous with the trypsin gene of Pacific White Shrimp(Litopenaeus vannamei) and consisted of one intron and two incomplete extrons. The deduced protein of the sequence has 182 amino acid residues and possesses all the key amino acids characteristics of the serine protease family. The catalytic active site is composed of the canonical triads of His, Asp and Ser and a specificity pocket occupied by Asp and the residues Gly, which define the trypsin specificity pocket. Phylogenetic analysis was processed with the amino acid sequence and protein sequences of the other 11 species’ trypsin genes. The result is the same as the present taxonomy according to the characteristic surface configuration. |
| Key words: Neocaridina denticulata sinensis trypsin gene phylogeny |
