Matsuoka M, Kano-Murakami Y, Tanaka Y, Ozeki Y, Yamamoto N
National Institute of Agrobiological Resources, Tsukuba Science City, Ibaraki.
J Biochem. 1987 Oct;102(4):673-6. doi: 10.1093/oxfordjournals.jbchem.a122103.
We have cloned a full length cDNA for the small subunit of ribulose-1,5-bisphosphate carboxylase from C4 monocot maize, determined the complete nucleotide sequence of this cDNA and deduced its amino acid sequence. The cDNA insert included 513 bp of the coding region, and 65 and 252 nucleotides of the 5' and 3' untranslated regions, respectively. The transit and mature peptides have, respectively, 47 and 123 amino acids. Comparison with the small subunit genes from other plants revealed that the maize small subunit is similar to the wheat one, there being 73% homology between the transit peptides and 64% between the mature proteins. This indicates that there is no noteworthy difference between the C3 and C4 small subunit structures. Extreme codon bias was observed for this gene, and similar codon preferences are observed for other proteins highly expressed in maize leaf, light harvesting chlorophyll binding protein and phosphoenolpyruvate carboxylase. The results indicate that preferential codon usage for highly expressed genes occurs in maize leaf.
我们已克隆出C4单子叶玉米中1,5 - 二磷酸核酮糖羧化酶小亚基的全长cDNA，测定了该cDNA的完整核苷酸序列，并推导了其氨基酸序列。该cDNA插入片段包括513 bp的编码区，以及分别为65和252个核苷酸的5'和3'非翻译区。转运肽和成熟肽分别有47和123个氨基酸。与其他植物的小亚基基因比较表明，玉米小亚基与小麦的相似，转运肽之间有73%的同源性，成熟蛋白之间有64%的同源性。这表明C3和C4小亚基结构之间没有显著差异。该基因存在极端的密码子偏好性，并且在玉米叶片中高表达的其他蛋白质，如捕光叶绿素结合蛋白和磷酸烯醇式丙酮酸羧化酶中也观察到类似的密码子偏好。结果表明，玉米叶片中高表达基因存在优先密码子使用现象。
