ASSEMBLY OF THE ACTIVE FORM OF THE TRANSPOSASE-MU DNA COMPLEX - A CRITICAL CONTROL POINT IN MU-TRANSPOSITION
ASSEMBLY OF THE ACTIVE FORM OF THE TRANSPOSASE-MU DNA COMPLEX - A CRITICAL CONTROL POINT IN MU-TRANSPOSITION
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DOI：
10.1016/0092-8674(92)90104-k
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发表时间：
1992-07-24
期刊：
影响因子：
64.5
通讯作者：
MIZUUCHI, K
中科院分区：
文献类型：
--
作者：
MIZUUCHI, M;BAKER, TA;MIZUUCHI, K
Mu DNA转座中一种新中间体的发现和鉴定使转座机制的组装与重组的化学步骤分开。这种稳定的中间体在有钙离子存在的情况下积累，由Mu转座酶四聚体与Mu DNA突触的两端组成。在这个稳定的突触复合体(SSC)中，重组位点已经参与，但尚未被切割。因此，SSC在结构上与裂解的供体和链转移复合体有关，但在转座途径上先于它们。一旦活性蛋白质-DNA复合体被构建，它在整个转座过程中都是保守的。在SSC组装过程中，仅有内部序列元件和辅助因子的参与，使得重组在不可逆转的化学步骤之前得到控制。
Discovery and characterization of a new intermediate in Mu DNA transposition allowed assembly of the transposition machinery to be separated from the chemical steps of recombination. This stable intermediate, which accumulates in the presence of Ca2+, consists of the two ends of the Mu DNA synapsed by a tetramer of the Mu transposase. Within this stable synaptic complex (SSC), the recombination sites are engaged but not yet cleaved. Thus, the SSC is structurally related to both the cleaved donor and strand transfer complexes, but precedes them on the transposition pathway. Once the active protein-DNA complex is constructed, it is conserved throughout transposition. The participation of internal sequence elements and accessory factors exclusively during SSC assembly allows recombination to be controlled prior to the irreversible chemical steps.