Ogawara H, Urabe H, Ohtaki R, Nakamura Y
Department of Biochemistry, Meiji College of Pharmacy, Tokyo, Japan.
J Bacteriol. 1995 Sep;177(18):5342-5. doi: 10.1128/jb.177.18.5342-5345.1995.
A gene was cloned from Streptomyces coelicolor A3(2). It encodes a protein of 368 amino acid residues with a high degree of similarity to prokaryotic release factor 2. However, it has neither an internal stop codon nor the Shine-Dalgarno-like sequence immediately upstream of the assumed frameshift position. The gene is expressed and functional in Escherichia coli as peptide chain release factor 2. The transcription start site is at or adjacent to the translational start site. The size of the mRNA detected by hybridization suggests that the gene (prfB) is monocistronic in S. coelicolor A3(2). However, about 80 bp upstream of the gene there is an operon which is composed of two genes encoding eukaryotic-type serine/threonine kinases.
从天蓝色链霉菌A3(2)中克隆出一个基因。它编码一个由368个氨基酸残基组成的蛋白质，与原核生物释放因子2高度相似。然而，它既没有内部终止密码子，也没有在假定移码位置上游紧邻的类似Shine-Dalgarno序列。该基因在大肠杆菌中作为肽链释放因子2表达且具有功能。转录起始位点在翻译起始位点处或其附近。通过杂交检测到的mRNA大小表明该基因（prfB）在天蓝色链霉菌A3(2)中是单顺反子的。然而，在该基因上游约80 bp处有一个操纵子，它由两个编码真核型丝氨酸/苏氨酸激酶的基因组成。
