Ogura K, Kajita J, Narihata H, Watabe T, Ozawa S, Nagata K, Yamazoe Y, Kato R
Department of Hygienic Chemistry, Tokyo College of Pharmacy, Japan.
Biochem Biophys Res Commun. 1990 Feb 14;166(3):1494-500. doi: 10.1016/0006-291x(90)91036-r.
A cDNA encoding hydroxysteroid sulfotransferase a (STa), which catalyzes activation of carcinogenic polycyclic hydroxymethyl-arenes, was isolated from a lambda gtll cDNA expression library constructed from poly(A)+RNA of a female Sprague-Dawley (SD) rat liver. The cDNA, designated as ST-40, consisted of 1,015 base pairs which had an open reading frame of 852 base pairs encoding the entire rat STa subunit of 284 amino acids. The nucleotide base sequence of the ST-40 cDNA shared a strong homology of 94.4% with that of ST-20 cDNA encoding a hydroxysteroid ST which had been reported by us. The deduced amino acid sequence of STa had a homology of 73.7% with that of an SD rat liver senescence marker protein (SMP-2) consisting of 282 amino acid residues. However, STa was found to share a much stronger homology of 92% on the average with SMP-2 in their four specific regions corresponding to about 60% of the total sequences, indicating SMP-2 to be an isozyme of hydroxysteroid ST.
从用雌性斯普拉格-道利（SD）大鼠肝脏的聚腺苷酸加尾RNA构建的λgtll cDNA表达文库中分离出一个编码羟基类固醇硫酸转移酶a（STa）的cDNA，该酶催化致癌多环羟甲基芳烃的活化。该cDNA被命名为ST-40，由1015个碱基对组成，其中有一个852个碱基对的开放阅读框，编码284个氨基酸的完整大鼠STa亚基。ST-40 cDNA的核苷酸碱基序列与我们报道的编码羟基类固醇硫酸转移酶的ST-20 cDNA的核苷酸碱基序列有94.4%的高度同源性。推导的STa氨基酸序列与由282个氨基酸残基组成的SD大鼠肝脏衰老标记蛋白（SMP-2）的氨基酸序列有73.7%的同源性。然而，发现STa在其四个特定区域与SMP-2平均有更强的92%的同源性，这些区域约占总序列的60%，表明SMP-2是羟基类固醇硫酸转移酶的一种同工酶。
