ROLE OF THE IS50R PROTEINS IN THE PROMOTION AND CONTROL OF TN5 TRANSPOSITION
ROLE OF THE IS50R PROTEINS IN THE PROMOTION AND CONTROL OF TN5 TRANSPOSITION
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DOI：
10.1016/0022-2836(84)90042-1
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发表时间：
1984-01-01
影响因子：
5.6
通讯作者：
REZNIKOFF, WS
中科院分区：
文献类型：
--
作者：
JOHNSON, RC;REZNIKOFF, WS
IS50R, the inverted repeat sequence of Tn5 which is responsible for supplying functions that promote and control Tn5 transposition, encodes 2 polypeptides that differ at their N terminus. Frameshift, in-frame deletion, nonsense and missense mutations within the N-terminus of protein 1 (which is not present in protein 2) were isolated and characterized. The properties of these mutations demonstrate that protein 1 is absolutely required for Tn5 transposition. None of these mutations affected the inhibitory activity of IS50, confirming that protein 2 is sufficient to mediate inhibition of Tn5 transposition. The effects on transposition of increasing the amount of protein 2 (the inhibitor) relative to protein 1 (the transposase) were also analyzed. Relatively large amounts of protein 2 were required to significantly decrease the transposition frequency of an element. Varying the coordinate synthesis of the IS50R proteins over a 30-fold range had little effect on the transposition frequency. Thus, neither the wild-type synthesis rate of protein 2 relative to protein 1 nor the amount of synthesis of both IS50R proteins is the only factor responsible for controlling the transposition frequency of a wild-type Tn5 element in Escherichia coli.
