Murphy E
Plasmid. 1983 Nov;10(3):260-9. doi: 10.1016/0147-619x(83)90040-9.
Tn554, a transposon in Staphylococcus aureus that specifies resistance to erythromycin and spectinomycin, exhibits a high preference for a single chromosomal insertion site. If this site is already occupied by a copy of Tn554, the transposition of a second element is inhibited 100- to 1000-fold. This report defines the locus of the inhibitory activity and presents both a functional and a restriction map of Tn554. Fragments containing parts of Tn554 were cloned on an autonomously replicating plasmid. Those clones containing the "left" end of Tn554 strongly inhibited the transposition of an incoming, intact copy of Tn554. Analysis of deleted derivatives of these clones defined a locus tnpI, which is both necessary and sufficient for transpositional inhibition. This locus consists of the terminal 89 bp of the "left" end of Tn554. It is suggested that this terminal sequence acts to titrate a factor required for transposition.
Tn554是金黄色葡萄球菌中的一种转座子，它赋予对红霉素和壮观霉素的抗性，对单个染色体插入位点表现出高度偏好。如果该位点已被Tn554的一个拷贝占据，第二个元件的转座会受到100至1000倍的抑制。本报告确定了抑制活性的位点，并给出了Tn554的功能图谱和限制酶切图谱。含有Tn554部分片段的片段被克隆到一个自主复制质粒上。那些含有Tn554“左端”的克隆强烈抑制了导入的完整Tn554拷贝的转座。对这些克隆的缺失衍生物的分析确定了一个位点tnpI，它对于转座抑制既是必需的也是充分的。该位点由Tn554“左端”的末端89个碱基对组成。有人提出，这个末端序列起到滴定转座所需因子的作用。
