Oh S J, Lee M C, Cho Y G, Kim J K, Nahm B H
Department of Biological Science, Myong Ji University, Yongin, Korea.
Mol Cells. 1998 Apr 30;8(2):175-80.
A cDNA clone (RA138) encoding a rice allergenic (RA) protein has been isolated during a large-scale random sequencing of a cDNA library prepared from developing seeds. The nucleotide sequence of the RA138 gene contained an open reading frame (ORF, 477 bp) encoding a 17 kDa protein. The amino acid sequence deduced from the ORF was composed of 159 amino acid residues and was highly homologous to those from RA genes previously isolated, such as RA5 (92% identity), RA14 (73%), and RA17 (68%). The protein contained 10 cysteine residues that were conserved in the alpha-amylase/trypsin inhibitor family including RA proteins. Excluding a putative signal peptide consisting of 26 amino acid residues, the mature protein would be 14.4 kDa in size and have a pI of 7.0. DNA gel blot analysis under high stringency conditions indicated that multiple copies of the RA138 gene were present in the rice genome. The chromosomal location of the RA138 gene has been identified on chromosome 7 in a segregation analysis using a population of 164 recombinant inbred lines derived from a cross between Milyang 23 and Gihobyeo. The locus that may contain multiple copies of the RA138 was located between RFLP markers RG477A and C492 with genetic distances of 10.7 cM and 6.7 cM, respectively.
在对发育种子制备的cDNA文库进行大规模随机测序过程中，分离出了一个编码水稻变应原（RA）蛋白的cDNA克隆（RA138）。RA138基因的核苷酸序列包含一个编码17 kDa蛋白的开放阅读框（ORF，477 bp）。从该ORF推导的氨基酸序列由159个氨基酸残基组成，与先前分离的RA基因（如RA5，同一性92%；RA14，73%；RA17，68%）的氨基酸序列高度同源。该蛋白含有10个半胱氨酸残基，在包括RA蛋白在内的α-淀粉酶/胰蛋白酶抑制剂家族中是保守的。除去由26个氨基酸残基组成的假定信号肽，成熟蛋白大小为14.4 kDa，pI为7.0。高严格条件下的DNA凝胶印迹分析表明，水稻基因组中存在多个拷贝的RA138基因。在使用由密阳23和吉霍比奥杂交产生的164个重组自交系群体进行的分离分析中，已确定RA138基因在第7号染色体上的位置。可能含有多个RA138拷贝的位点位于RFLP标记RG477A和C492之间，遗传距离分别为10.7 cM和6.7 cM。
