Foster T J, Davis M A, Roberts D E, Takeshita K, Kleckner N
Cell. 1981 Jan;23(1):201-13. doi: 10.1016/0092-8674(81)90285-3.
Transposon Tn10 is 9300 bp in length, with 1400 bp inverted repeats at its ends. The inverted repeats are structurally intact IS-like sequences (Ross et al., 1979). Analysis of deletion mutants and structural variants of Tn10, reported below, shows that the two IS10 segments contain all of the Tn10-encoded genetic determinants, both sites and functions, that are required for transposition. Furthermore, the two repeats (IS10-Right and IS10-Left) are not functionally equivalent: IS10-Right is fully functional and is capable by itself of promoting normal levels of Tn10 transposition; IS10-Left functions only poorly by itself, promoting transposition at a very low level when IS10-Right is inactivated. Complementation analysis shows that IS10-Right encodes at least one function, required for Tn10 transposition, which can act in trans and which works at the ends of the element. Also, all of the sites specifically required for normal Tn10 transposition have been localized to the outermost 70 bp at each end of the element; there is no evidence that specific sites internal to the element play an essential role. Finally, Tn10 modulates its own transposition in such a way that transposition-defective point mutants, unlike deletion mutants, are not complemented by functions provided in trans; and wild-type Tn10, unlike deletion mutants, is not affected by functions provided in trans from a "high hopper" Tn10 element.
转座子Tn10长度为9300碱基对，其末端有1400碱基对的反向重复序列。这些反向重复序列是结构完整的类插入序列（IS）（罗斯等人，1979年）。下面报道的对Tn10缺失突变体和结构变体的分析表明，两个IS10片段包含了转座所需的所有Tn10编码的遗传决定因素，包括位点和功能。此外，两个重复序列（IS10-右和IS10-左）在功能上并不等同：IS10-右功能完全正常，能够自身促进正常水平的Tn10转座；IS10-左自身功能很差，当IS10-右失活时，它只能促进极低水平的转座。互补分析表明，IS10-右编码至少一种Tn10转座所需的功能，该功能可以反式作用，并且在元件末端起作用。此外，正常Tn10转座所需的所有位点都已定位到元件两端最外侧的70碱基对；没有证据表明元件内部的特定位点起关键作用。最后，Tn10以这样一种方式调节自身的转座，即与缺失突变体不同，转座缺陷型点突变体不能被反式提供的功能互补；与缺失突变体不同，野生型Tn10不受来自“高跳跃者”Tn10元件的反式提供的功能的影响。
