Horikawa S, Ishikawa M, Ozasa H, Tsukada K
Department of Pathological Biochemistry, Tokyo Medical and Dental University, Japan.
Eur J Biochem. 1989 Oct 1;184(3):497-501. doi: 10.1111/j.1432-1033.1989.tb15042.x.
We have isolated cDNA clones encoding the rat liver S-adenosylmethionine synthetase by means of immunological screening from a phage lambda gt 11 expression library containing cDNA synthesized from adult rat liver poly(A)-RNA. The amino acid sequence deduced from the cDNA indicates that the rat liver enzyme for this protein contains 397 amino acid residues and has a molecular mass of 43697 Da. The deduced amino acid sequence of rat liver S-adenosylmethionine synthetase was 68% similar to those of yeast S-adenosylmethionine synthetases encoded by two unlinked genes SAM1 and SAM2. The rat liver S-adenosylmethionine synthetase also shows 52% similarity with the deduced amino acid sequence of the MetK gene encoding the S-adenosylmethionine synthetase in Escherichia coli.
我们通过免疫筛选，从一个含有从成年大鼠肝脏多聚腺苷酸RNA合成的cDNA的λgt 11噬菌体表达文库中分离出了编码大鼠肝脏S-腺苷甲硫氨酸合成酶的cDNA克隆。从该cDNA推导的氨基酸序列表明，这种蛋白质的大鼠肝脏酶含有397个氨基酸残基，分子量为43697道尔顿。推导的大鼠肝脏S-腺苷甲硫氨酸合成酶的氨基酸序列与由两个不连锁基因SAM1和SAM2编码的酵母S-腺苷甲硫氨酸合成酶的序列有68%的相似性。大鼠肝脏S-腺苷甲硫氨酸合成酶与编码大肠杆菌S-腺苷甲硫氨酸合成酶的MetK基因推导的氨基酸序列也有52%的相似性。
