小麦脂质转运蛋白cDNA结构及相应肽链构造特征的分析

Sequence Analysis of Wheat Lipid Transfer Protein cDNA and the Structural Characteristics of Corresponding Peptide

根据测序获得的1条261 bp cDNA片段,通过电子延伸、设计引物,从小麦Mardler/7*百农3217(Pm2)的cDNA中扩增获得1条651 bp的cDNA片段,通过同源比对发现其包含小麦LTP1完整的编码序列。该片段包含基因的5′非翻译区42 bp,3′非翻译区261 bp,开放阅读框348 bp,编码115个氨基酸,预计蛋白的分子量为11.2 kD,等电点为9.46。此基因有8个位置保守的半胱氨酸(C)残基及25个氨基酸的信号肽,为典型的植物脂质转运蛋白基因。其基因序列数据库(GenBank)登录号为AY796184(基因)和AAV65513(蛋白)。通过疏/亲水性分析,发现肽链分子具有较大范围的疏水面。

One of the sequenced eDNA fragments was highly identified with LTP1. The EST was extended using CAP3 software in the lab local net. Based on the extended sequence, a pair of primers was designed in the two side regions of its predicted ORF. Using RT-PCR method, a eDNA fragment of 651 bp was isolated from Mardler/7^＊ BaiNong 3217. It was found that this eDNA contained the complete coding sequence of LTP1 of wheat including 42 bp of 5＇ untranslated region, 261 bp of 3＇ untranslated region, and an open reading frame （ORF） of 348 bp. The ORF region encoded a peptide of 115 deduced amino acid residues. The deduced molecular weight of protein was 11.2 kD and its isoelectric point was 9.46. This gene contained 8 eysteine residues that were conserved in amino acid sequence, and had a signal peptide with 25 amino acids. It was a typical plant LTP gene. The gene was accepted by GenBank, the accession numbers were AY796184 （gene） and AAV65513 （protein）. The hydropathy profile revealed that the putative peptide chain contained several hydrophobie regions.