Characterization of a low-molecular-weight glutenin subunit gene from bread wheat and the corresponding protein that represents a major subunit of the glutenin polymer
Characterization of a low-molecular-weight glutenin subunit gene from bread wheat and the corresponding protein that represents a major subunit of the glutenin polymer
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DOI：
10.1104/pp.118.4.1147
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发表时间：
1998-12-01
期刊：
影响因子：
7.4
通讯作者：
Kasarda, DD
中科院分区：
文献类型：
--
作者：
Masci, S;D'Ovidio, R;Kasarda, DD
高分子量麦谷蛋白亚基和低分子量麦谷蛋白亚基（LMW-GS）在决定小麦（Triticum aestivum L.）面粉到目前为止，DNA测序得到的LMW-GS的氨基酸序列与胚乳中实际存在的LMW-GS的氨基酸序列之间没有明确的对应关系。我们已经确定了一个特殊的LMW-GS从六倍体面包小麦，麦谷蛋白聚合体的主要成分，我们称之为42 K LMW-GS，并已分离和测序推定的相应基因。直接获得的42 K LMW-GS的广泛的氨基酸序列表明该蛋白质和推定的相应基因之间的对应关系。该亚基在位置5处没有显示半胱氨酸（Cys），这与经常报道的LMW-GS的基于核苷酸的序列相反。该Cys已被重复序列结构域中出现的Cys取代，使得分子中Cys残基的总数与各种其他LMW-GS中相同。根据推导的氨基酸序列和文献中二硫键的归属，构建了42 K亚基的计算机分子模型。
Both high- and low-molecular-weight glutenin subunits (LMW-GS) play the major role in determining the viscoelastic properties of wheat (Triticum aestivum L.) flour. To date there has been no clear correspondence between the amino acid sequences of LMW-GS derived from DNA sequencing and those of actual LMW-GS present in the endosperm. We have characterized a particular LMW-GS from hexaploid bread wheat, a major component of the glutenin polymer, which we call the 42K LMW-GS, and have isolated and sequenced the putative corresponding gene. Extensive amino acid sequences obtained directly for this 42K LMW-GS indicate correspondence between this protein and the putative corresponding gene. This subunit did not show a cysteine (Cys) at position 5, in contrast to what has frequently been reported for nucleotide-based sequences of LMW-GS. This Cys has been replaced by one occurring in the repeated-sequence domain, leaving the total number of Cys residues in the molecule the same as in various other LMW-GS. On the basis of the deduced amino acid sequence and literature-based assignment of disulfide linkages, a computer-generated molecular model of the 42K subunit was constructed.