THE MOLECULAR-BASIS FOR RIBOSOMAL-RNA-DEPENDENT SPECTINOMYCIN RESISTANCE IN NICOTIANA CHLOROPLASTS
THE MOLECULAR-BASIS FOR RIBOSOMAL-RNA-DEPENDENT SPECTINOMYCIN RESISTANCE IN NICOTIANA CHLOROPLASTS
复制标题
DOI：
10.1002/j.1460-2075.1987.tb02640.x
复制
发表时间：
1987-11-01
期刊：
影响因子：
11.4
通讯作者：
GALUN, E
中科院分区：
文献类型：
--
作者：
FROMM, H;EDELMAN, M;GALUN, E
分析了几个抗大观霉素突变体的叶绿体16S核糖体RNA编码基因。鉴定了两类突变体。在一类中，在烟草叶绿体16S rRNA基因的位置1140处发现G到A碱基的转换，其消除了Aat II限制性内切酶位点。这种碱基转换接近于先前描述的大肠杆菌中壮观霉素抗性的突变体。在另一类中，在16S rRNA基因的位置1012处发现了一种新的G到A的转换。虽然这两类突变相距128个核苷酸，但16S rRNA的二级结构模型表明，这两个突变的核苷酸在分子3“区域中保守茎结构的相对侧上空间接近。系统发育的证据，这一保守的茎连接大观霉素抗性叶绿体。茎的扰动被认为是rRNA依赖性大观霉素抗性的分子遗传基础。
The chloroplast genes coding for the 16S ribosomal RNA from several spectinomycin-resistant Nicotiana mutants were analyzed. Two classes of mutants were identified. In one class, a G to A base transition is found at position 1140 of the tobacco-chloroplast 16S rRNA gene, which eliminates an AatII restriction endonuclease site. This base transition is proximal to a mutant previously described for spectinomycin resistance in Escherichia coli. In the other class, a novel G to A transition is found at position 1012 of the 16S rRNA gene. Although the mutations in the two classes are 128 nucleotides apart, the secondary structure model for 16S rRNA suggests that the two mutated nucleotides are in spatial proximity on opposite sides of a conserved stem structure in the 3'' region of the molecule. Phylogenetic evidence is presented linking this conserved stem with spectinomycin resistance in chloroplasts. Perturbation of the stem is proposed to be the molecular-genetic basis for rRNA-dependent spectinomycin resistance.