Base changes at position 792 of Escherichia coli 16S rRNA affect assembly of 70S ribosomes.
Base changes at position 792 of Escherichia coli 16S rRNA affect assembly of 70S ribosomes.
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大肠杆菌 16S rRNA 792 位碱基变化会影响 70S 核糖体的组装。
DOI：
10.1073/pnas.87.10.3700
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发表时间：
1990
影响因子：
11.1
通讯作者：
McLaughlin,J
中科院分区：
文献类型：
--
作者：
Santer,M;Bennett-Guerrero,E;Byahatti,S;Czarnecki,S;O'Connell,D;Meyer,M;Khoury,J;Cheng,X;Schwartz,I;McLaughlin,J
为了研究大肠杆菌 30S 核糖体中 16S rRNA 792 碱基的功能，通过寡核苷酸定向诱变将野生型（腺嘌呤）残基改为鸟嘌呤、胞嘧啶或尿嘧啶。每个碱基变化都赋予细胞独特的表型。含有质粒 pKK3535 和 G792 或 T792 的细胞在含有氨苄青霉素的 LB 肉汤中表现出世代时间没有差异，而含有 C792 的细胞在该培养基中表现出世代时间增加 20%。为了研究同质突变核糖体群体对细胞生长的影响，将突变克隆到携带壮观霉素抗性标记（第 1192 位胸腺嘧啶）的 pKK3535 上的 16S rRNA 基因中，并用壮观霉素培养细胞。含有 G792 或 C792 的细胞显示世代时间分别增加了 16% 和 56%，并且伴随着 35S 同化蛋白质的减少。带有 T792 的细胞不能在含有奇霉素的培养基中生长。 Maxicell 分析表明，16S rRNA 792 位含有鸟嘌呤、胞嘧啶或尿嘧啶的 30S 亚基形成 70S 核糖体的能力下降。看来含有 C792 的 30S 核糖体已经失去了结合起始因子 3 的能力。
To investigate the function of base 792 of 16S rRNA in 30S ribosomes of Escherichia coli, the wild-type (adenine) residue was changed to guanine, cytosine, or uracil by oligonucleotide-directed mutagenesis. Each base change conferred a unique phenotype on the cells. Cells containing plasmid pKK3535 with G792 or T792 showed no difference in generation time in LB broth containing ampicillin, whereas cells with C792 exhibited a 20% increase in generation time in this medium. To study the effect on cell growth of a homogeneous population of mutant ribosomes, the mutations were cloned into the 16S rRNA gene on pKK3535 carrying a spectinomycin-resistance marker (thymine at position 1192), and the cells were grown with spectinomycin. Cells containing G792 or C792 showed 16% and 56% increases in generation time, respectively, and a concomitant decrease in 35S assimilation into proteins. Cells with T792 did not grow in spectinomycin-containing medium. Maxicell analyses indicated decreasing ability to form 70S ribosomes from 30S subunits containing guanine, cytosine, or uracil at position 792 in 16S rRNA. It appeared that C792-containing 30S ribosomes had lost the ability to bind initiation factor 3.