Ozeki K, Kitamoto K, Gomi K, Kumagai C, Tamura G, Hara S
National Research Institute of Brewing, Tokyo, Japan.
Curr Genet. 1991 May;19(5):367-73. doi: 10.1007/BF00309597.
Using synthetic oligonucleotide probes, we have cloned a genomic DNA sequence encoding a ribonuclease (RNase) T2 gene (rntB) from Aspergillus oryzae on a 4.8 kb HindIII fragment. DNA sequence analysis of the RNase T2 revealed the following: (1) The gene is arranged as five exons and four introns; (2) The deduced amino acid sequence contains 239 amino acid residues of the mature enzyme. In addition, there exist 17 amino acid residues thought to be a signal peptide sequence at the N-terminus and 20 amino acid residues at the C-terminus; (3) The nucleotide sequence of the rntB gene is homologous to those of the RNase Rh gene from Rhizopus niveus and the S2 stylar glycoprotein gene of Nicotiana alata with degree of about 51% and 47%, respectively; (4) A. oryzae and A. nidulans transformed with the cloned rntB gene had much higher ribonuclease T2 activity than wild-type strains.
利用合成寡核苷酸探针，我们从米曲霉中克隆出了一个编码核糖核酸酶（RNase）T2基因（rntB）的基因组DNA序列，该序列位于一个4.8 kb的HindIII片段上。对RNase T2的DNA序列分析结果如下：（1）该基因由五个外显子和四个内含子组成；（2）推导的氨基酸序列包含成熟酶的239个氨基酸残基。此外，在N端存在17个被认为是信号肽序列的氨基酸残基，在C端存在20个氨基酸残基；（3）rntB基因的核苷酸序列分别与雪白根霉的RNase Rh基因和烟草花柱糖蛋白基因S2的核苷酸序列具有约51%和47%的同源性；（4）用克隆的rntB基因转化的米曲霉和构巢曲霉的核糖核酸酶T2活性比野生型菌株高得多。
