Nomura H, Inokuchi N, Kobayashi H, Koyama T, Iwama M, Ohgi K, Irie M
Department of Microbiology, College of Pharmacy, Nihon University.
J Biochem. 1994 Jul;116(1):26-33. doi: 10.1093/oxfordjournals.jbchem.a124498.
A guanine nucleotide-specific RNase (RNase Po1) was isolated from caps of the fruit bodies of Pleurotus ostreatus. RNase Po1 is most active towards RNA at pH 8.0. The effect of heating on the molar ellipticity at 210 nm of RNase Po1 showed that RNase Po1 is more stable than RNase T1. The primary structure of RNase Po1 was determined to be < ETGVRSCNCAGRSFTGTDVTNAIRSARAGGSGNYPHVYNNFEGFSFSCTPTFFEFPVFRGSVYSGGSPG ADRVIYD- QSGRFCACLTHTGAPSTNGFVECRF. It consisted of 101 amino acid residues, with a molecular weight of 10,760. RNase Po1 has relatively higher sequence homology with RNase T1 family RNase. It contains 6 half cystine residues. The locations of four of them are superimposable on those of RNase U1 and RNase U2. The amino acid residues forming the active site of RNase T1 were well conserved in this RNase. Therefore, RNase Po1 is a unique member of the RNase T1 family in respect of the location of one disulfide bridge, and its stability.
从平菇子实体的菌盖中分离出一种鸟嘌呤核苷酸特异性核糖核酸酶（核糖核酸酶Po1）。核糖核酸酶Po1在pH 8.0时对RNA的活性最高。加热对核糖核酸酶Po1在210nm处的摩尔椭圆率的影响表明，核糖核酸酶Po1比核糖核酸酶T1更稳定。核糖核酸酶Po1的一级结构确定为<ETGVRSCNCAGRSFTGTDVTNAIRSARAGGSGNYPHVYNNFEGFSFSCTPTFFEFPVFRGSVYSGGSPG ADRVIYD- QSGRFCACLTHTGAPSTNGFVECRF。它由101个氨基酸残基组成，分子量为10760。核糖核酸酶Po1与核糖核酸酶T1家族核糖核酸酶具有相对较高的序列同源性。它含有6个半胱氨酸残基。其中4个的位置与核糖核酸酶U1和核糖核酸酶U2的位置重叠。在这种核糖核酸酶中，形成核糖核酸酶T1活性位点的氨基酸残基得到了很好的保守。因此，就一个二硫键的位置及其稳定性而言，核糖核酸酶Po1是核糖核酸酶T1家族的一个独特成员。
