CSIRO Division of Plant Industry, GPO Box 1600, 2601, Canberra, A.C.T., Australia.
Planta. 1990 Mar;180(4):461-70. doi: 10.1007/BF02411442.
Convicilin, a trimeric globulin of pea (Pisum sativum L.) seeds, is closely related to vicilin and composed of polypeptides of 68.2 kilodaltons. A partial copy DNA (cDNA) clone encoding convicilin was isolated, sequenced, and used to select a convicilin gene from a pea genomic library. A part of the genomic clone was sequenced to obtain the coding sequences missing in the cDNA clone and a further 1 kilobase 5' to the start of transcription were also obtained. The entire sequence of convicilin was deduced from the combined genomic and cDNA sequences. The complete gene encoding convicilin was transferred to tobacco (Nicotiana tabacum L.) and the characteristics of its expression in the seeds of transgenic plants were studied. An unprocessed polypeptide, which was found only in the seeds of the transgenic plants, was identical in size to pea convicilin, and was recognized by vicilin antibodies. Convicilin, which does not undergo posttranslational cleavage in peas, was partially processed to polypeptides of a relative molecular mass (Mr) of approx. 50000 in transgenic tobacco seeds. There was a twofold variation in the level of convicilin accumulated by the mature seeds of a number of transgenic plants and this was well correlated with the number of gene copies incorporated in the different transformants. In the seeds of tobacco plants that contained a single copy of the transferred gene it was estimated that convicilin comprised up to 2% of the seed protein. Thus, using a combination of gene sequencing and expression in a heterologous host we believe we have characterized the gene corresponding to theCvc locus, whereas the gene described by D. Bown et al. (1988, Biochem J.,251, 717-726) probably encodes a minor convicilin-related protein.
豌豆（Pisum sativum L.）种子球蛋白 convicilin 是一种三聚体球蛋白，与 vicilin 密切相关，由 68.2 千道尔顿的多肽组成。分离并测序了编码 convicilin 的部分 cDNA 克隆，并利用该 cDNA 克隆从豌豆基因组文库中选择 convicilin 基因。对基因组克隆的一部分进行测序，以获得 cDNA 克隆中缺失的编码序列，并进一步获得转录起始点上游的 1 千碱基。从组合的基因组和 cDNA 序列推导出 convicilin 的整个序列。将完整的 convicilin 基因转移到烟草（Nicotiana tabacum L.）中，并研究了其在转基因植物种子中的表达特征。在转基因植物的种子中仅发现一种未经加工的多肽，其大小与豌豆 convicilin 相同，并被 vicilin 抗体识别。在豌豆中，convicilin 不经历翻译后切割，在转基因烟草种子中部分加工成相对分子质量（Mr）约为 50000 的多肽。许多转基因植物成熟种子中 convicilin 的积累水平存在两倍的差异，这与不同转化体中整合的基因拷贝数密切相关。在含有转移基因单拷贝的烟草种子中，convicilin 估计占种子蛋白的 2%。因此，我们通过基因测序和在异源宿主中的表达相结合，认为我们已经鉴定了与 Cvc 基因座相对应的基因，而 D. Bown 等人描述的基因（1988 年，Biochem J.，251，717-726）可能编码一种次要的 convicilin 相关蛋白。
